Climatic factors | forestrynepal

Climatic factors | forestrynepal

Climatic factors has contributed to climatic change either direct or indirect. I recommend this website above to read, which talks about the factors (Solar radiation: a. Light, b. Heat and temperature, Moisture and wind). The writer go into details how they contributed to climatic change and you will see other references too.

References:
Climatic

Int J Dev Biol - Loss of plakophilin 2 disrupts heart development in zebrafish

Int J Dev Biol - Loss of plakophilin 2 disrupts heart development in zebrafish

This is interesting topic to read about the 'Loss of plakophilin 2 disrupts heart development in zebrafish.

The abstract talks about the desmosomal armadillo protein plakophilin 2 is the only plakophilin expressed in the heart, and mutation in the human plakophilin2 gene result in arrhythmogenic right ventricular cardiomyopathy.....

References:
http://www.ijdb.ehu.es/web/paper/113390mm/loss-of-plakophilin-2-disrupts-heart-development-in-zebrafish

World's big trees are dying: Alarming increase in death rates among trees 100-300 years old

This is amazing to read, because it talks about the declining of the largest trees around the globe! What is the causes of it? Check it out by yourself!!!!!







World's big trees are dying: Alarming increase in death rates among trees 100-300 years old
 References:
http://www.sciencedaily.com/releases/2012/12/121206162519.htm

Developmental Biology! Animal Body Plans of Development.

The body of animal form as part of an inherited developmental sequence and the sequence starts after fertilization of an egg produced by the ovary form a Zygote. And this Zygote is single big cell until the process of cleavage started dividing itself into a large number of smaller cells named Blastomeres.

The cleavage starts in several different patterns: cnidarians and sponges lack a distinct cleavage shape, but bilateral animals, exhibit either radial or spiral cleavage. Based on the Biologist, assumed that these two types of cleavage each evolved and the animals with spiral cleavage form a monophyletic group, compared to the animals with radial cleavage.

Radial cleavage are typical of echinoderms, chordates and hemichordates. It occurs with regulative development where each blastomere of the early embryo.

Spiral cleavage are typical of mollusks, annelids and other protostomes. It occurs in form of mosaic development, which the organ-forming determinants in the egg cytoplasm etc.

References:

www.wikipedia.com
Animal diversity 5th Edition.

Developmental Biology! Condition associated with abnormal male gonad development during early development stage!

The are many conditions that can leads to abnormal development of male sex gonads during the early

development starting from fertilization, cleavage, gastrulation and organogenesis period. We will

mention only two for today and hope we learn something interesting from it.

- -Klinefelter syndrome is the condition that resulted from extra ‘X’ chromosome

received by a male child during fertilization period. Klinefelter syndrome can leads to low or

shortage of testosterone at puberty and this can leads to breast enlargement

(gynecomastia), reduced the facial and body hair and unable to father a child in life. 

-- Absent of gene can leads to abnormality of sex male gonad during early

development of embryo. For example: Deletion or mutation of SRY gene will results

in failure to form testicle part and end up forming or developing ovary and females

reproductive parts in male child.

For many other conditions that contributed to abnormal male sex gonad development can be 

view from either 'wikipedia website' or other medical website for more references to view. 

Thank you for reading my blog and hope to see you next time again.      

References: 

www.wikipedia.com

www.nih.gov or National institute of Health domain.

The Element of Ecology! Effect of overpopulation in community.

What is overpopulation? According to wikipedia dictionary, overpopulation a generally undesirable condition where an organism's numbers exceed the carrying capacity of its habitat. Overpopulation occurs around the globe as well not just community in forest only and the consequence is very detrimental to the living organism and non-lilving organism too. These are effects of overpopulation as follow below:

1. Inadequate of food or scarcity of food in the community. 
2. Spread of disease around the community because of overcrowded among the group of different species in the community.
3. lack of space for habitation.
4. leads to change in temperature in the community.
5. increase in death rate and decrease in birth rate.
6. Lack of water or drought period.
7. Leads to competition within the community, either intraspecific or interspecific competition in the community.

There are many effects resulting from overpopulation in the community that is not mentioned, but you search online for many more. Thanks for reading and hope to see you next time again. 

References:
www.wikipedia.com
   

Developmental Biology! Topic: Summary of early amphibian development

Fertilization can occur anywhere in the animal hemisphere of the amphibian embryo, but the point of sperm entry is very imperative because it determines the orientation of the dorsal-ventral axis of the larva (tadpole). The point of sperm entry will mark the ventral side of the embryo, while the site 180 degrees opposite the point of sperm entry will mark the dorsal side.

Cleavage in most frog embryos is radially symmetrical and holoblastic, just like echinoderm cleavage. As we mentioned that amphibian cleavage is holoblastic, but it is unequal due to the presence of yolk in the vegetal hemisphere.

Gastrulation in amphibian begins with the invagination of the bottle cells, followed by the coordinated involution of the mesoderm and the epiboly of the ectoderm. The rotation of the vegetal pole plays a important role in directing the involution pattern. During gastrulation, the driving forces for ectoderm epiboly and the convergent extension of the mesoderm are the intercalation events in which several tissues layers merge. What play important role to make sure that mesodermal cell to migrate into the embryo? It is the Fibronectin.

The dorsal lip of the blastopore form the organizer tissue of the amphibian gastrula. The tissue dorsalizes the ectoderm, transforming it into neural tissues and transforms ventral mesoderm into lateral and dorsal mesoderm. The organizer comprises of pharyngeal endoderm, head mesoderm, notochord, and dorsal blastopore lip tissues. The organizer functions by secreting protein (Noggin, chord in, and follistatin) that block the BMP signal that would otherwise centralize the mesoderm and activate the epidermal gene in the ectoderm.

The organizer itself induced by the Nieuwkoop center, located in the dorsal most vegetal cells. This center is formed by the translocation of the Disheveled protein and Wnt11 to the coral side of the egg to stabilize beta-catenin in the dorsal cells of the embryo.

The Siamois and Twin protein collaborate with Smad2/4 transcription factors generated by the TGF beta pathway (Nodal, Vg1, and activin) to activate genes encoding BMP inhibitors. Noggin, chord in, and follistatin, as well as the transcription factor Goosecoid are the BMP inhibitors. When BMP inhibitors are present, the ectoderm cells form neural tissue, but the action of BMP on ectoderm cells causes them to become epidermis. For the head region, an additional set of proteins (Cerberus, Frzb, Dickkopf) block the Wnt signal from the ventral and lateral mesoderm.

Insulin-like growth factor (IGF) help transform the neural tube into anterior (forebrain) tissue.

This is just snap view of amphibian early development and you can look into other biology texts books or online developmental biology for more details and thanks for reading.

References:

www.wikipedia.com
Developemental Biology 9 edition by Scott F. Gilbert.

Element of Ecology! Topic: Interaction within the community

Interaction is common among different living species within a community and they can either cause interaction to reduced competition or predation, and the interaction can be direct or indirect interaction. We will focused on indirect interaction within a community. Direct interaction with a species is straight forward to understand, but indirect interaction is kind of different! Indirect interaction in food webs illustrate indirect interaction among species within the community. Indirect interaction can be define when one species does not interact with a second species directly, but influences a thirds species that does interact with second. For example, a predator may increase the population density of one or more inferior competitors by reducing the abundance of the superior competitor it preys on. We also have indirect positive interaction, result when one species benefits another indirectly through its interactions with others, reducing competition or predation in the community.

References:
Elements of Ecology 8 edition by Thomas M. Smith & Robert Leo Smith.

Developmental Biology! Fertilzation the starting juction to organogenesis!!

We must know that fertilization in vertebrate is as important as organogenesis because if anything went wrong it will surely affect the end of organogenesis. As we know that fertilization is the fusion of the mature sex cells, the sperm and the egg. It is very crucial that the male mature sex cell able to travel through the female reproductive path in order to penetrate the egg after been released and after the have sperm penetrated the egg then the next step is very important as well. After fertlization, is the cleavage where rapid mitotic divisions occur and they divided into smaller blastomeres, which the blastomeres fomred a sphere, known as a blastula. The blastocoel cavity in the beginning of gastrulation is important for allowing cell movement to occur during gastrulation period.

"It is not birth, marriage, or death, but gastrulation, which is truly the most important time in your life." Lewis Wolpert (1986).

After the rapid mitotic division in cleavage, thne gastrulation is the next where the blastomeres undergo dramatic movement and change their position relatives to one another. The series of cells rearragements is known as gastrulation and the embryo is said to be at the gastrula stage. At the end of the gastrulation results in three germ layers called Ectoderm, mesoderm and endoderm. And these three germ layers will interact to form organs needed for the development of the embryo and the is called organogenesis. Organogenesis is when three germ layers interact with one another  and rearrange themselves to produce tissues and organs.

Fnally, the quality of organs and tissues developed depends on the crucial stages that the fertilized egg path through from fertilization to organogenesis and there are essential stages that the embryo need to take and the rapid mitotic division, and their changing of cells positioning to formed tissues and organs.

References:

www.wikipedia.com
Developmental Biology. Ninth Edition by Scott Gilbert

The Element of Ecology! Food chain!

As we all know that every organisms either small or large or micro need to obtain energy for their survival in the habitat they live. The way the organisms feed or depend on other for food to metabolize their daily activity and the structural linear is know as food chain. According to wikipedia dictionary, 'A food chain is the sequence of who eats whom in a biological community (an ecosystem) to obtain nutrition.' Starting from the primary producer that depend on sunlight to make their nutrient and they are called autotroph or primary producers For examples; plants. And the next on is herbivores or primary consumers that feed on primary producers or autotroph organisms are 'grasshoppers' and follow by the next link chain called secondary consumers that feed on primary consumers e.g. rats. In secondary consumers stage, there are two type of feeding, one is carnivores (eating flesh) and omnivores (eating flesh and plants). The next is tertiary consumers that feeds on secondary consumers like snakes and the final one is the quaternary consumers feeds tertiary consumers to living. The predator at the bottom of food chain have less enemy, so they live longer than the primary producers, but the cycle of primary producers at the top of food chain is faster and they produce more in vast for the food cycle. After the bottom predator died, the detrivores (vultures, crabs)  feeds on the the quaternary consumers and they decomposed (by the decomposer like fungi and bacteria) as source of nutrients for the primary producers to grow. 

The picture of food chain from enchanted learning website below:

References:

www.wikipedia.com

www.enchantedlearning.com

Developmental Biology: Topic: Fibroblast growtth factor (FGF). Their functioning!

What is Fibroblast growth factor? Accroding to 'wikipedia dictionary', "Fibroblast growth factors, or FGFs, are a family of growth factors involved in angiogenesis, wound healings, and embryonic development. The FGFs are heparin-binding proteins and interactions with cell-surface-associated heparan sulfate proteoglycans have been shown to be essential for FGF signal transduction."


Members FGF1 through FGF10 all bind fibroblast growth factor receptors (FGFRs). FGF1 is also known as acidic, and FGF2 is also known as basic fibroblast growth factor. Members FGF11, FGF12, FGF13, and FGF14, also known as FGF homologous factors 1-4 (FHF1-FHF4), have been shown to have distinct functional differences compared to the FGFs. Although these factors possess remarkably similar sequence homology, they do not bind FGFRs and are involved in intracellular processes unrelated to the FGFs.

Receptors:
The mammalian fibroblast growth factor receptor family has 4 members, FGFR1, FGFR2, FGFR3, and FGFR4. The FGFRs consist of three extracellular immunoglobulin-type domains (D1-D3), a single-span trans-membrane domain and an intracellular split tyrosine kinase domain.

Function:
-  FGFs are important players in wound healing.
- FGF1 and FGF2 stimulate angiogenesis and the proliferation of fibroblasts that give rise to granulation tissue, which fills up a wound space/cavity early in the wound-healing process.
- FGFs are major determinants of neuronal survival both during development and during adulthood.
- In addition, FGF-1 and FGF-2 seem to be involved in the regulation of synaptic plasticity and processes attributed to learning and memory, at least in the hippocampus.
- FGF23 is produced by bone but acts on FGFR1-expressing kidney cells to regulate the synthesis of vitamin D and in turn affect calcium homeostasis.
- One important function of FGF1 and FGF2 is the promotion of endothelial cell proliferation and the physical organization of endothelial cells into tube-like structures.
- FGF is critical during normal development of both vertebrates and invertebrates and any irregularities in their function leads to a range of developmental defects.

References:
www.wikipedia.com

Element of Ecology! Topic: Impact of climate change on economical sector!

The rise in climate change will cost the US economy and we will mention five keys lesson that we must know as result of climate change as follow below:

1. Economic impacts of climate change will occur throughout the country, which means that the impact of climate change will affect the US economy all round the country and is not limited to certain states but all as whole. 
2. Economic impacts will be unevenly distributed across regions and within the economy and society, meaning the impact of the climate change will vary depending on certain region and their topography.
3. Negative climate impacts will outweigh benefits for most sectors that provide essential goods and services to society. As we all nkow that the rise in climate change has benefit, but the negative impact will out-weigh the benefit. 
4. Climate change impacts will place immense strains on public sector budgets. We must know that change in climate will have negative impact in budget of US, because more money wil be spend and other sector might be cut spending and that is not good.
5. Secondary effects of climate impacts can include higher prices, reduced income and job losses. As we know that uneployment rate is high around United State as nation, but the impact of climate change plays a major role in it, by incraese in gasoline and less employment opportunity for citizens, except the qualified educated ones that meet the standard jobs.

References:

www.epa.org.

Small fish: Big role in coastal carbon cycle! Developmental Biology!

Small fish: Big role in coastal carbon cycle








This study talks about how small habitats transform carbon dioxide from the atmosphere into the ocean which cause global warming. this is short paragraph from the website to see and you can also visit the above website for more information to see how it happen:

"Oct. 18, 2012 — A study in the current issue of Scientific Reports, a new online journal from the Nature Publishing Group, shows that small forage fish like anchovies can play an important role in the "biological pump," the process by which marine life transports carbon dioxide from the atmosphere and surface ocean into the deep sea—where it contributes nothing to current global warming.
The study, by Dr. Grace Saba of Rutgers University and professor Deborah Steinberg of the Virginia Institute of Marine Science, reports on data collected during an oceanographic expedition to the California coast during Saba's graduate studies at VIMS. Saba, now a post-doctoral researcher in Rutgers' Institute of Marine and Coastal Research, earned her Ph.D. from the College of William and Mary's School of Marine Science at VIMS in 2009. The expedition, aboard the research vessel Point Sur, was funded by the National Science Foundation.
The study's focus on fish is a departure for Steinberg and colleagues in her Zooplankton Ecology Lab, who typically study tiny crustaceans called copepods. Research by Steinberg's team during the last two decades has revealed that copepods and other small, drifting marine animals play a key role in the biological pump by grazing on photosynthetic algaenear the sea surface, then releasing the carbon they've ingested as "fecal pellets" that can rapidly sink to the deep ocean. The algal cells are themselves generally too small and light to sink.
"'Fecal pellet' is the scientific term for "poop," laughs Steinberg. "Previous studies in our lab and by other researchers show that zooplankton fecal pellets can sink at rates of hundreds to thousands of feet per day, providing an efficient means of moving carbon to depth. But there have been few studies of fecal pellets from fish, thus the impetus for our project."

Refrences:

www.macroevolution.net/marine-carbon-cycle.html

The Element of Ecology! Topic: Factors affecting birth rate!

What is birth rate? According to wikipedia, ' The birth rate is typically the rate of births in a population over time. The rate of births in a population is calculated in several ways: live births from a universal registration system for births, deaths, and marriages; population counts from a census, and estimation through specialized demographic techniques.' 

Factors affecting birth rate as follow:

1. Government policy: Government policy affect birth rate, for example is pronatalist or antinatalist ( tax on childlessness).
2. Availability of family planning such like, birth control and sex education among the communities.
3. Safety abortion and safety child birth in the community.
4. Illiteracy and unemployment factors can affect birth rate.
5. High poverty level within the nation can affect birth rate.
6. Long term economic difficulty can affect birth rate, because married couple that is facing financial problem tend to delay child bearing for some reason. 
7. Religious and social belief can affecting birth rate, in term of abortion and contraception. 

References:
www.wikipedia.com 

Developmental Biology! The Cycle of Life.

The generalized life cycle in animal is one of the major triumphant  descriptive of embryology and each  animal, whether frog, human being or others has a similar stages of development. The stages of development between fertilization and delivery or hatching are uniformly called 'EMBRYOGENESIS.'





Embryonic has a six fundamental processes and we will mention as follow below:

1. Fertilization: this involves the fusion of the matured male and female sex cells and they are collectively called gametes. once the fertilization occurred, it stimulate the development of the egg into initial new specie and continue to the next stage called cleavage.

2. Cleavage is a continuous rapid mitotic divisions that immediately follow after fertilization and during this cleavage, mass number of zygote cytoplasm is divided into smaller cells called Blastomeres. At the end of cleavage formed the a sphere called blastula.

3. Gastrulation: After the fast rate of mitotic cell division slow down, the blastomeres undergoes a rearrangement of position relatives to one another. And the series of cell rearrangement is called gastrulation and at this stage, the embryo is called gastrula stage which this stage of gastrulation result to three germ layers that interact with each other to form organs of the body.

4. Organogenesis: Once the three germ layers is finally established, the cells interact with one another and rearranged themselves, then they produce tissues and organs; and the process is called organogenesis.

5. In some species, the organism that hatches from the egg is not sexually mature, but rather, the organism need to undergoes metamorphosis to become a sexually mature adult. According to wikipedia, 'Metamorphosis is a biological process by which an animal physically develop after birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation."

6. in many species, the group of cells are put aside to formed the next generation. These mentioned cells are the precursors of the gametes. The germ cells are the collectively of the gametes and their precursor and they are set aside for productive physiology and others cells of the body are somatic cells. The separation of the somatic cells give rise to the individual body and the germ cells contributes to new generation.

References:

www.wikipedia.com
Developmental Biology ninth edition, by Scott F. Gilbert.

Ecology! Soil Profile!

SOIL PROFILE PICTURE BELOW:


  





Soil profile is also know as soil horizon and according to wikipedia definition, " A soil horizon is a layer parallel to the soil surface, whose physical characteristics differ from the layers above and beneath. Each soil type has at least one, usually three or four horizons. Horizons are defined in most cases by obvious physical features, chiefly colour and texture. These may be described both in absolute terms (particle size distribution for texture, for instance) and in terms relative to the surrounding material, i.e. ‘coarser’ or ‘sandier’ than the horizons above and below."

1. The 'O' zone is the organic layer dominated by organic material consisting of un-decomposed or partially  decomposed plant material.
2. The 'A' zone is the topsoil and is largely mineral soil developed from parent material; organic matter leached from above gives this horizon a distinctive dark color.
3. The 'B' zones the subsoil and is accumulation of mineral particles, such as clay and salts leached from topsoil.
4. The 'C' zone is unconsolidated material derived from the original parent material from which the soil developedFinally, the collectively sequences of horizontal layers constitutes a soil profile and this pattern of horizontal layers is visible to see from fresh cut been made along a road bank for a building site.
References:
www.wikipedia.com
Element of Ecology Text Book.

Developmental Biology! Sex determination in Reptile.

                

Temperature dependent sex determination

See also: Temperature-dependent sex determination

Many other sex-determination systems exist. In some species of reptiles, including alligators, some turtles, the tuatara, sex is determined by the temperature at which the egg is incubated during a temperature sensitive period. There are no examples of temperature-dependent sex determination (TSD) in birds (including megapodes, which had formerly been thought to exhibit this phenomenon, but actually exhibit temperature-dependent embryo mortality).^[28] For some species with TSD, sex determination is achieved by hotter temperatures being one sex and cooler temperatures being the other. For others, the extreme temperatures are one sex and the middle temperature is the other. These temperature thresholds are known as Pattern I and Pattern II, respectively. The temperatures required for the specific sexes are known as the female promoting temperature and the male promoting temperature.^[29] When the temperature stays near the threshold during the temperature sensitive period, the sex ratio is varied between the two sexes.^[30] Some species set their temperature standards based on when an enzyme is created. These species that rely upon temperature for their sex determination do not have the SRY gene, but have other genes such as DAX1, DMRT1, and SOX9 that are expressed or not expressed depending on the temperature.^[29] Some species such as the Nile Tilapia, Australian skink lizard, and Australian dragon lizardhave sex determined by chromosomes, but this can later be switched by the temperature of incubation.^[9] These species seem to be in a transitional state of evolution.

It is unknown how exactly temperature sex determination evolved.^[31] It could have evolved through certain sexes being more suited to certain areas that fit the temperature requirements. For example, a warmer area could be more suitable for nesting, so more females are produced to increase the amount that nest next season. However, at this stage it's mostly hypotheses.

Other sex determination systems

While temperature dependent sex determination is relatively common, there are many other environmental systems. Some species, such as some snails, practice sex change: adults start out male, then become female. In tropical clown fish, the dominant individual in a group becomes female while the other ones are male, and bluehead wrasses (Thalassoma bifasciatum) are the reverse. In the marine worm (Bonellia viridis), larvae become males if they make physical contact with a female, and females if they end up on the bare sea floor. This is triggered by the presence of a chemical produced by the females, bonellin. Some species, however, have no sex-determination system. Hermaphrodites include the common earthworm and certain species of snails. A few species of fish, reptiles, and insects reproduce by parthenogenesis and are female altogether. There are some reptiles, such as the boa constrictor and komodo dragon that can reproduce sexually and asexually, depending if a mate is available.^[32] In the case of the boa constrictor, it can create both male and female offspring parthenogenetically.

In some arthropods, sex is determined by infection, as when bacteria of the genus Wolbachia alter their sexuality; some species consist entirely of ZZ individuals, with sex determined by the presence ofWolbachia.^[33]

Other unusual systems (this section is still being researched):

References:

www.wikipedia.com

Ecology! Environmental factors to human health.

According to the Environmental Protection Agency, cancer, cardiovascular disease, respiratory disease, infectious disease, and birth defects are all associated with exposure to environmental contaminants, and all occur in epidemic proportions in the U.S.
There are currently 85,000 chemicals on the market in this country – 20,000 more than were available in the 1970s – and only a few hundred have been tested for their safety. Lowering the levels of chemicals in our environment has the potential to lower rates of death and disease, and literally make us feel better.

According to the government agency (EPA), mentioned all these associated with environmental factors that prone health negatives to human being around the globe as followed below:

In the 42 years since Earth Day was founded, more attention has been brought to the dangers of pollution and global warming, to the importance of recycling, and the “green” lifestyle I’ve championed for decades. But a lot of other changes have occurred, many of them negative, most of them toxic, and nearly all of them preventable.
On Earth Day 2012, let’s consider some of these trends, how they have affected our health, and aim to make them obsolete.
Food derived from genetically modified organisms (GMOs) pervades the U.S. market because they resist pests and increase crop yields. These foods have had specific changes introduced to their DNA by engineering techniques, and include soybeans, corn, canola, rice, dairy, and more.
Such ingredients are hidden in nearly all processed foods, and can cause health concerns like allergies, antibiotic resistance, and liver problems. GMO foods can be avoided by purchasing 100 percent organic items, shopping locally, buying whole foods or growing your own food.
Babies are being born pre-polluted, meaning industrial chemicals have been found in umbilical cord blood – 200 on average, according to a 2009 report by the Environmental Working Group. In 2010, the President’s Cancer Panel at the National Cancer Institute noted that health officials still lack critical knowledge about the health impact of chemicals on fetuses and children.
The oceans now contain “dead zones,” which are parts of the sea floor along the coasts of major continents that have very low concentrations of oxygen. As a result, few organisms can survive there. According to NASA’s Goddard Earth Sciences Data and Information Services Center, the apparent cause of dead zones is fertilizer, which runs off fields, into streams, and eventually the ocean. Additionally, the North Pacific Ocean contains something called The Great Pacific Garbage Patch, two large masses of trash that scientists estimate is twice the size of Texas, and hazardous to marine life, fishing, and tourism. Recycling and proper trash disposal has never been more imperative!
The U.S. is replete with factory farms, which confine thousands of animals in awful, dirty circumstances and pump them full of antibiotics, all in the name of food production. Such farms generate huge amounts of manure containing deadly pathogens, antibiotics, drug-resistant bacteria, hormones, heavy metals, ammonia, and hydrogen sulfide that can seriously impact human health, as David Kirby details in his book Animal Factory. The activities on factory farms create massive amounts of pollution that harms the people living nearby, according to the Humane Society of the United States, not to mention what the meat from overfed, diseased animals can do to your body.

References:
http://voices.rodale.com/the-top-environmental-factors-affecting-your-health/2012/04/23/

Posted by Akinola on October 12, 2012.