Seasonal Variations of Small Wading Birds in the Pichavaram Mangrove Forest, India

The Pichavaram Mangrove Forest (PMF) is one of the important wetlands in southern India. The PMF is harboring numerous species of shorebirds seasonally. The current study assessed the population characteristics of small wading birds by using direct count method from 2015 to 2016. In total, 27 species of small wading birds were recorded, in which the Little stint showed highest density 177.24±20.515 (No./ha.) and the Bar-tailed godwit showed lowest density 0.13±0.099 (No./ha.). Indeed the Little stint was only species turned highest density across the three different seasons studied. However, the bar-tailed godwit not recorded during the pre-monsoon and post-monsoon seasons, the Dunlin, Grey plover and Great sand plover not sighted during the post-monsoon season. The density, diversity and species richness of small wading birds showed significant differences among the seasons (P<0.001). The study inferred that the population characteristics of small wading birds are declining when compared to the previous studies. However exhaustive studies are essential to explore the quality of the PMF which is need of the hour since it is supporting various species of shorebirds seasonally.

Experimental infection by Borrelia anserina strain PL in Gallus gallus

Avian borreliosis is a tick-borne acute septicemic disease that affects a variety of avian species and is caused by the bacterium Borrelia anserina. The present study aimed to establish the infection dynamics of B. anserina in experimentally infected Gallus gallus to determine its impact on the health and weight gain of the animals. Forty G. gallus were divided into four groups. Group 1 (G1) included 10 animals inoculated intramuscularly (IM) with 250μL of blood serum containing 3.7x106 spirochetes per milliliter. Group 2 (G2) included 10 animals inoculated IM with 250μL of saline 0.9%. Group 3 (G3) included 10 animals infested with four Argas miniatus nymphs (3rd instar) infected with B. anserina strain PL. Group 4 (G4) included 10 animals infested with four A. miniatus nymphs (3rd instar) free of infection by B. anserina. The number of spirochetes in the blood was directly proportional to the appearance of clinical signs and symptoms. This is the first study showing the experimental clinical evolution of the B. anserina PL strain in G. gallus. Additionally, the first assessments of spirochetaemia are presented, based on the direct count of bacteria in the serum by a Neubauer chamber, during the infection.

Distribution and abundance of aerobic anoxygenic phototrophic bacteria in the tropical coastal waters of Gunungkidul, Yogyakarta, Indonesia

Aprilyanto V, Sembiring L, Djohan TS. 2020. Distribution and abundance of aerobic anoxygenic phototrophic bacteria in the tropical coastal waters of Gunungkidul, Yogyakarta, Indonesia. Biodiversitas 21: 5506-5513. Aerobic anoxygenic phototroph (AAP) is a community of bacteria capable of performing anoxygenic photosynthesis in the presence of oxygen. AAP abundance in most oceanic regions signals its ecological importance in marine microbial loop. This study was conducted to reveal the distribution and abundance of AAP in Siung coast, Gunungkidul, Yogyakarta, Indonesia. Total bacterioplankton and AAP were enumerated using acridine orange direct count (AODC) and real-time quantitative PCR (qPCR), respectively. Several water physicochemical parameters as well as dissolved nitrate, ammonium, phosphate, and sulfate were also measured. The results showed that total bacterioplankton was distributed thoroughly in the water column with abundance ranging from 2.5×104 to 3.5×104 cells/mL. Within this total bacterioplankton, AAP ranged from 3.83×102 –7.48×102 cells/mL, comprising about 1% to ~2.5%. Inorganic nutrient concentration, mainly nitrate and phosphate were thought to be the regulating factors to the distribution and abundance of both communities. In conclusion, AAP comprises a relatively low portion of the total bacterioplankton community in the tropical coastal water in Gunungkidul, Yogyakarta.

Comparison of methods for quantifying primordial follicles in the mouse ovary

Background Accurate evaluation of primordial follicle numbers in mouse ovaries is an essential endpoint for studies investigating how endogenous and exogenous insults, such as maternal aging and chemotherapy, impact the ovarian reserve. In this study, we compared and contrasted two methods for counting healthy primordial follicles following exposure to cyclophosphamide (75 mg/kg), a well-established model of follicle depletion. The first was the fractionator/optical dissector technique, an unbiased, assumption-free stereological approach for quantification of primordial follicle numbers. While accurate, highly reproducible and sensitive, this method relies on specialist microscopy equipment and software, requires specific fixation, embedding and sectioning parameters to be followed, and is largely a manual process that is tedious and time-consuming. The second method was the more widely used serial section and direct count approach, which is relatively quick and easy. We also compared the impacts of different fixatives, embedding material and section thickness on the overall results for each method. Results Direct counts resulted in primordial follicle numbers that were significantly lower than those obtained by stereology, irrespective of fixation and embedding material. When applied to formalin fixed tissue, the direct count method did not detect differences in follicle numbers between saline and cyclophosphamide treated groups to the same degree of sensitivity as the gold standard stereology method (referred to as the Reference standard). However, when Bouin’s fixative was used, direct counts and stereology were comparable in their ability to detect follicle depletion caused by cyclophosphamide. Conclusions This work indicates that the direct count method can produce similar results to stereology when Bouin’s fixative is used instead of formalin. The findings presented here will assist others to select the most appropriate experimental approach for accurate follicle enumeration, depending on whether the primary objective of the study is to determine absolute primordial follicle numbers or relative differences between groups.

Distribution of Royle’s Pika Ochotona roylei in Parvati Kunda Groundwater Complex

Royle’s Pika Ochotona roylei is high altitude animal belonging to the family Ochotonidae in order Lagomorpha. Royle’s Pika was reported in different locations between an elevation of 2180 to 5950 meters above sea level (m asl). This study carried in February and October 2017 recorded a small population of Royle’s Pika in the Parvati Kunda Groundwater Complex of Gatlang village in Rasuwa District, Nepal. A total of 12 Royle’s pika individuals were head counted from three sites while Pika foraged plants were observed in other sites. Pika was observed in talus groove amidst Rhododendron-fir forest, Fir-hemlock forest, and Rhododendron shrub close to the alpine meadow. Pika in the study was distributed from the Parvati Kunda wetland proximity at an elevation of 2605 m with a direct count of 2 individuals to an elevation of 3000 m asl beneath Tshumer hill with a headcount of 7 individuals. However, the population of Royle’s Pika in the area was estimated more. The population density of 6 individuals/hectare was calculated in the area, which is relatively lower than the population density accounted for in other areas.

Greater One-horned Rhinoceros Rhinoceros unicornis (Mammalia: Perissodactyla: Rhinocerotidae) population census in the Rajiv Gandhi Orang National Park, Assam, India

The complete-count of rhino or rhino census is an integral part of conservation and management of wild rhino-bearing areas of Assam. The direct count of rhinos in their wild habitat continues as the accepted method of determining rhino population. As a part of the periodic process, the Rajiv Gandhi Orang National Park (RGONP) organized a one-day direct rhino count on 2 April 2018. The results showed 1% increment of the population after a gap of six years. Such slow increment is considered to be a matter of concern. More research is necessary for better understanding of the population dynamics and identification of factors for better management of rhino population at RGONP.

The ecology of viruses

In addition to grazing, another form of top-down control of microbes is lysis by viruses. Every organism in the biosphere is probably infected by at least one virus, but the most common viruses are thought to be those that infect bacteria. Viruses come in many varieties, but the simplest is a form of nucleic acid wrapped in a protein coat. The form of nucleic acid can be virtually any type of RNA or DNA, single or double stranded. Few viruses in nature can be identified by traditional methods because their hosts cannot be grown in the laboratory. Direct count methods have found that viruses are very abundant, being about ten-fold more abundant than bacteria, but the ratio of viruses to bacteria varies greatly. Viruses are thought to account for about 50% of bacterial mortality but the percentage varies from zero to 100%, depending on the environment and time. In addition to viruses of bacteria and cyanobacteria, microbial ecologists have examined viruses of algae and the possibility that viral lysis ends phytoplankton blooms. Viruses infecting fungi do not appear to lyse their host and are transmitted from one fungus to another without being released into the external environment. While viral lysis and grazing are both top-down controls on microbial growth, they differ in several crucial respects. Unlike grazers, which often completely oxidize prey organic material to carbon dioxide and inorganic nutrients, viral lysis releases the organic material from hosts more or less without modification. Perhaps even more important, viruses may facilitate the exchange of genetic material from one host to another. Metagenomic approaches have been used to explore viral diversity and the dynamics of virus communities in natural environments.

Pengaruh Polyethylene Fiber pada Material Resin Komposit terhadap Jumlah Koloni Candida albicans

Fiber reinforced composite (FRC) is a material combination of polymer matrix and fiber. Fiber that commonly used in dentistry is polyethylene fiber due its resistance to abrasion. During placement of FRC in mouth, interaction will occur between the material with mucosa, saliva, and microorganisms. Candida albicans is one of many microorganisms present in oral. The purpose of this study was to determine the effect of addition polyethylene fiber on composite resin to C. albicans colony counts. Flowable composite and polyethylene fiber are material used in this study. Bar-shaped samples which sized 5x4x2 mm (n=4) immersed in 5 ml saliva for 1 hour, then immersed in suspension containing C. albicans and incubated for 2 hours at 37°C. The suspension was diluted to 10 then 0.1 mL were put in a solid medium and incubated for 48 hours at 37°C. The amount of C. albicans was determined by direct count. Data were statistically analyzed by using unpaired t-test.The result of unpaired t-test showed a significance differences of C. albicans colony between composite resin and FRC with polyethylene fiber (p <0.05). The conclusion was there was a significant increasing number of C. albicans colonies on composite resin with addition of polyethylene fiber.

Pengaruh Polyethylene Fiber pada Material Resin Komposit Terhadap Jumlah Koloni Streptococcus mutans

Fiber reinforced composite (FRC) is a material made of polymer matrix and fiber. Polyethylene fiber is one of the commonly used fiber due its good strength. FRC in the oral cavity will interact with saliva and microorganisms.S. mutans is microorganisms present in oral cavity. The purpose of this study was to determine the effect ofpolyethylene fiber on FRC to S. mutans colony counts. Flowable composite and polyethylene fiber are material used in this study. Bar-shaped samples sized 5 x 4 x 2 mm (n = 4) immersed in 5 mL saliva for 1 hour, then immersed in suspension containing S. mutans and incubated for 24 hours at 37°C. The suspension diluted to 10 then 0.1 mL of the dilution were put in a solid medium and incubated for 48 hours at 37°C. Streptococcus mutans were grown on solid media was determined by direct count. Data were statistically analyzed using unpaired t-test. The results of unpaired t-test showed a significance difference of S. mutans colony between composite resin and FRC with polyethylene fiber (p <0.05). The conclusion from this study was the addition of polyethylene fiber on the composite material significantly increased the number of colonies of Streptococcus mutans.