Evaluation of conservation interventions using a cellular automata-Markov model

The field of biodiversity conservation increasingly recognizes the need for empirical evaluations of conservation interventions. While the amount of money invested into conservation and the number of protected areas across the globe have been increasing in the past few decades, few well-designed empirical studies try to show what could have happened in the absence of the conservation efforts. In this paper, we propose an empirical method to evaluate such conservation intervention. We integrate a cellular automata-Markov modeling approach and a counterfactual approach showing what may have happened in the absence of a certain conservation intervention. We test this method in a human-dominated tropical landscape in Central India; however, our method is transferable to any other socio-ecological setting. The study area is located in the tropical forests of Central India and has witnessed several management strategies since its declaration as a protected area in the mid-1970s. However, landscape practitioners have identified the revised forest policy of 1988 to play a vital role in this landscape. We chose this particular forest policy as the conservation intervention in our study and tested our method using this landscape as a template. We used remote sensing and GIS techniques to analyze multi-sensor satellite data from the last 30 years to monitor forest transitions and compare them with the counterfactual scenario. Our findings not only shed light on the importance of national-level policies in governing forest dynamics, but also established our proposed method as an effective tool for empirical evaluation of conservation intervention, particularly in developing countries.     

Carbondioxide gating in silk cocoon

Silk is the generic name given to the fibrous proteins spun by a number of arthropods. During metamorphosis, the larva of the silk producing arthropods excrete silk-fiber from its mouth and spun it around the body to form a protective structure called cocoon. An adult moth emerges out from the cocoon after the dormant phase (pupal phase) varying from 2 weeks to 9 months. It is intriguing how CO(2)/O(2) and ambient temperature are regulated inside the cocoon during the development of the pupa. Here we show that the cocoon membrane is asymmetric, it allows preferential gating of CO(2) from inside to outside and it regulates a physiological temperature inside the cocoon irrespective of the surrounding environment temperature. We demonstrate that under simulating CO(2) rich external environment, the CO(2) does not diffuse inside the cocoon. Whereas, when CO(2) was injected inside the cocoon, it diffuses out in 20 s, indicating gating of CO(2) from inside to outside the membrane. Removal of the calcium oxalate hydrate crystals which are naturally present on the outer surface of the cocoon affected the complete blockade of CO(2) flow from outside to inside suggesting its role to trap most of the CO(2) as hydrogen bonded bicarbonate on the surface. The weaved silk of the cocoon worked as the second barrier to prevent residual CO(2) passage. Furthermore, we show that under two extreme natural temperature regime of 5 and 50 °C, a temperature of 25 and 34 °C respectively were maintained inside the cocoons. Our results demonstrate, how CO(2) gating and thermoregulation helps in maintaining an ambient atmosphere inside the cocoon for the growth of pupa. Such natural architectural control of gas and temperature regulation could be helpful in developing energy saving structures and gas filters.     

Relation of soya bean meal level to the concentration of plasma free amino acids and body growth in white rats

Amino acid (AA) levels in plasma and body growth were determined in rats (n20) fed diets with different soya bean meal levels. Free AA in plasma was determined by reversed-phase high-pressure liquid chromatography. We have used four levels of protein diets like 8%, 15%, 23% and 35% in this trial. Rats which were fed the low-protein (8%) diet with low percentage of soya bean meal were found to be growth-retarded. The body weight gain of high protein group (35%) was lower than that of the 23% groups. In the rats fed with the low-soya bean meal diet, some nonessential AA (NEAA) in plasma like asparagine, aspartic acid, cysteine, glutamic acid and serine increased, whereas the essential AA (EAA), with the exception of arginine, methionine and valine decreased. Here, plasma EAA-to-NEAA ratios were not correlated to growth and experimental diet. We hypothesize that AA metabolism is associated to changes in growth in rats on different protein intake. This study has showed the sensitivity of body mass gain, feed intake, feed conversion rate of rats to four levels of protein in the diet under controlled experimental conditions.     

Arsenic contamination in cropping systems under varying irrigation sources in the deltaic plain of India

A field experiment was conducted in an arsenic endemic area of West Bengal, India (22°57?N, 89°33?E) in 2010–2012 to understand different prevalent cropping systems of the area as to nature of arsenic uptake by the crops and influence of different sources of irrigation water. The experiment was laid out in split plot design consisting two irrigation managements [I₁: irrigation with shallow tube well (STW) and I₂: irrigation from harvested pond water (PW)] in main plot and four cropping systems in sub plot were C₁: pea- summer rice- cowpea, C₂: potato- green gram- elephant foot yam (EFY), C₃: wheat- jute- winter rice and C₄: French bean- sesame- winter rice. Irrigation from PW recorded less arsenic uptake compared to STW. Arsenic uptake was minimum with French bean- sesame- winter rice (C₄), followed by potato – green gram – EFY (C₂). System equivalent yield was the highest with C₂. The highest return was recorded with C₂ and the return per dollar (USD) investment was the maximum with C₁, followed by C₂. Potato- green gram- EFY (C₂) proved to be the better option for the farmers in arsenic contaminated area with greater yield potential, highest return per dollar investment and less arsenic uptake.     

Maternal antibody to infectious bronchitis virus: its role in protection against infection and development of active immunity to vaccine

Chicks hatched with high levels of maternal antibody had excellent protection (>95%) against infectious bronchitis virus (IBV) challenge at 1 day of age, but not at 7 days (<30%). This protection significantly (P<0.05) correlated with levels of local respiratory antibody and not with serum antibody.A high percentage of both maternal antibody-positive (Mab+) and maternal antibody-negative (Mab-) chicks failed to produce IBV antibody when vaccinated at 1 day of age by the intraocular route. In addition, Mab+ chickens had a weaker virus-neutralizing antibody response to a second IBV vaccination compared to Mab- birds (P<0.05). Mab+ chicks experienced a more rapid decline (P<0.01) in maternal antibody after 1-day-of-age vaccination compared to their unvaccinated counterparts.A monoclonal antibody-based blocking ELISA that measured antibody levels specific to S1 glycoprotein of IBV correlated well with virus-neutralizing antibody titers.     

Establishment of persistent avian infectious bronchitis virus infection in antibody-free and antibody-positive chickens

Avian infectious bronchitis virus (IBV) causes a highly contagious and economically significant disease in chickens. Establishment of a carrier state in IBV infection and the potential for the persistent virus to undergo mutations and recombination in chicken tissues have important consequences for disease management. Nevertheless, whether chickens can maintain persistent IBV infection in the absence of reinfection from exogenous sources or the presence of antibody in the host can modulate virus persistence remains unclear. Indeed, whether or not IBV genome can undergo genetic changes during in vivo infection has not been demonstrated experimentally. In the present study, IBV shedding and tissue persistence were monitored in individual chickens maintained under strict isolation that precluded reinfection from exogenous sources. In the first of two experiments, intranasal exposure of 6-wk-old antibody-free chickens to IBV vaccine virus resulted in intermittent shedding of the virus from both trachea and cloaca of individual birds for up to 63 days. Also, the virus was recovered from the internal organs (spleen, gonad, kidney, lung, cecal tonsil, and cloacal bursa) of six of eight birds killed at various intervals between 27 and 163 days postinoculation (DPI). In the second experiment, IBV exposure of 1-day-old maternal antibody-positive chicks led to periodic virus shedding from the trachea and cloaca in all chickens until 77 days; however, internal organs (lungs and kidneys) of only one of seven birds (killed at 175 DPI) were virus positive, suggesting that presence of antibody at the time of infection protects internal organs from IBV infection. When the lung and kidney isolates of IBV from the latter experiment were compared with the parent-vaccine virus, no changes in their antigenicity, tissue tropism, or the nucleotide sequence of the S1 glycoprotein gene were observed. These findings indicate that, unlike the mammalian coronaviruses, propensity for frequent genetic change may not be inherent in the IBV genome.     

Characterization of infectious bronchitis virus isolates by slot blot hybridization

We used slot blot hybridization of the hypervariable regions of the S1 subunit of spike peplomer gene to identify and characterize infectious bronchitis virus (IBV) strains. Template DNA was created from six reference strain IBVs of different serotypes and immobilized on a nitrocellulose membrane. We synthesized digoxigenin-labeled probes from reference and unknown field viruses and hybridized them to template DNA. All reference strains could be distinguished and isolates identified by serotype if they were at least 95% identical to a reference strain. This slot blot hybridization procedure was specific and reproducible, and strain typing was consistent with the S1 sequencing of the IBV genome. This study thus provides a simple and rapid method for typing of IBV.     

Plasma growth hormone concentrations in female mithun (Bos frontalis) of different ages: relations with age and body weight

The role of growth hormone (GH) in postnatal somatic growth is well established. Its basal level and relation to growth performance in different age group mithun (Bos frontalis), a semiwild ruminant has not been characterized until now. To estimate the normal blood GH level and also to assess the influence of age and body weight (BW) on blood GH level in captive mithuns, a total of 65 female mithuns was divided into six age groups (group I, 0-6 months; group II, >6-12 months; group III, >1-2 years; group IV, >2-2.5 years; group V, >2.5-3.0 years and group VI, >3.0 years). Blood samples collected weekly for six consecutive weeks were assayed for GH. GH was also estimated in the samples collected from six growing mithuns at -60, -45, -30, -15, -10, -5 and 0 min prior to GH-releasing hormone (GHRH) administration for calculation of basal GH level and at 5, 10, 15, 30 min and thereafter at 15-min interval up to 8 h post-GHRH to assess blood GH response following GHRH administration in growing mithuns. For calculation of basal plasma GH in adult mithuns, GH was measured in blood samples collected at 30-min interval for 24 h from four animals. BW of all animals was recorded on two consecutive days per week and average of weekly BW was considered for growth rate calculation. It was found that both mean GH and GH per 100 kg BW between the age groups differ (p < 0.01). With increasing age and BW, GH and GH per 100 kg BW both decreased (p < 0.01). The age group with higher plasma GH and GH per 100 kg BW showed higher growth rates (r = 0.83 and 0.97 respectively). Interestingly, mean plasma GH for six consecutive weeks in all the groups showed much greater GH concentration (group I, 86.6 +/- 9.7 ng/ml to group VI 33.2 +/- 5 ng/ml) than reported in other species. Mean basal plasma GH calculated in growing and adult mithuns was 29.6 +/- 4.01 ng/ml and around 25 +/- 3.6 ng/ml respectively. The GH peak (444 +/- 21.3 ng/ml) was registered at 15 min post-GHRH administration in growing mithuns. In conclusion, age and BW influence plasma GH and GH per 100 kg BW but the latter is a better indicator of growth. The basal plasma GH and GH response to GHRH administration is six to eight and four to five times higher in mithun than in other species reported so far. An accurate assessment of the relationship between GH profiles and protein metabolism, proper receptor level study for GH action at the cellular level and the interaction of GH with other growth factors awaits better understanding of higher GH in this unique species.     

NITRATE ACCUMULATION IN SPINACH AS INFLUENCED BY SULFUR AND PHOSPHORUS APPLICATION UNDER INCREASING NITROGEN LEVELS

Nitrate (NO₃) accumulation by spinach was studied under increasing nitrogen (N) levels (60, 120 and 240 kg N ha^?1) along with sulfur (45 kg S ha^?1) and phosphorus (P; 90 kg P₂O₅ ha^?1) application. Plants were harvested at 50 and 65 days after sowing. Plant samples were analyzed for NO₃-N and total N, P, S, potassium (K), calcium (Ca), and magnesium (Mg). Radio assay of 35S was done to estimate percent sulfur derived from fertilizer and percent fertilizer sulfur utilization. Spinach maintained a very high level of NO₃-N in its tissue throughout the growing period. NO₃-N was increased with increasing nitrogen level and was reduced with phosphorus and sulfur application and also with advancement in growth. Total N, P, S, K, Ca and Mg uptake were increased with increasing nitrogen levels as well as with application of sulfur and phosphorus. Sulfur application caused increase in percent sulfur derived from fertilizer and percent utilization of fertilizer sulfur.