Cypermethrin and λ-cyhalothrin induced alterations in nucleic acids and protein contents in a freshwater fish, <Emphasis Type="Italic"> Channa punctatus</Emphasis>

In this study, a freshwater fish Channa punctatus was exposed to subacute concentrations of synthetic pyrethroid insecticides (cypermethrin and λ-cyhalothrin) for 96 h to evaluate their impact on the levels of nucleic acids and protein in its different organs. Significant enhancement in the level of DNA was recorded in all tissues of the fish at high concentration of cypermethrin, whereas RNA and protein contents increased in tissues at all concentrations of cypermethrin tested. In contrast, λ-cyhalothrin treatment caused an increase in the level of DNA only in liver and brain, whereas increase of RNA and protein varied to different levels in different tissues. Cypermethrin treatment induced RNA/DNA ratio in all fish organs tested, whereas λ-cyhalothrin caused a sharp decrease in the ratio. Protein/DNA ratios were found to be tissue specific in treatments with both of the insecticides. The results clearly indicated that both of these pyrethroids exerted their effects in a similar manner in fish liver but differed in other tissues. These insecticides acted as potential biomodulators in C. punctatus, though following different routes. The results may be an indicator of aquatic pollution affecting freshwater fauna and flora and thus signaling the need for strict regulation on the indiscriminate input of pyrethroids from agricultural sites.     

Marker‐assisted introgression of lpa2 locus responsible for low‐phytic acid trait into an elite tropical maize inbred (Zea mays L.)

Maize is an important food and feed crop worldwide. Phytic acid (PA), in maize kernel, is an antinutritional factor. PA chelates mineral cations and causes mineral deficiency in humans and phosphorous deficiency in animals. The undigested PA excreted by monogastric animals causes phosphorous eutrophication. Therefore, development of low‐phytate maize is indispensable. The low‐phytate locus (lpa2 allele) has been transferred from low‐phytate mutant line ‘EC 659418’ into an elite inbred UMI 395 through marker‐assisted backcross breeding (MABB). The MABB involved three backcrosses followed by two selfing steps, including ‘foreground selection’, that is, selecting lines with lpa2 allele with the help of a codominant SSR marker ‘umc2230’ and ‘background selection’, that is, selecting plants having genetic background similar to that of the recurrent parent using 50 codominant SSR markers. Two low‐phytate lpa2 lines with genome similar (>90% similarity) to that of recurrent parent have been identified. These lines can be used as parent in future hybridization programmes for obtaining low‐phytate high‐yielding maize hybrids.     

Translocation of 14C-sucrose within the Ear in Durum and Aestivum Wheat Varieties

Excised ears of Triticum durum (HD 4502 and B 449) and T. aestivum (Kalyansona and Kundan) varieties were cultured in ¹⁴C-sucrose, and the uptake and distribution of ¹⁴C within the ear was examined. Species-level differences in the distribution of ¹⁴C to spikelets at basal, middle and apical positions in the wheat ear (vertical distribution) were observed. T. aestivum var. Kalyansona and Kundan showed no limitation in vertical translocation of ¹⁴C-sucrose, whereas in T. durum there was a decrease in the distribution of ¹⁴C to apical spikelets. Within a spikelet, the distribution of ¹⁴C-sucrose to distal grains was significantly less than that to proximal grains in all the genotypes.     

Developmentally regulated piRNA clusters implicate MILI in transposon control

Nearly half of the mammalian genome is composed of repeated sequences. In Drosophila, Piwi proteins exert control over transposons. However, mammalian Piwi proteins, MIWI and MILI, partner with Piwi-interacting RNAs (piRNAs) that are depleted of repeat sequences, which raises questions about a role for mammalian Piwi's in transposon control. A search for murine small RNAs that might program Piwi proteins for transposon suppression revealed developmentally regulated piRNA loci, some of which resemble transposon master control loci of Drosophila. We also find evidence of an adaptive amplification loop in which MILI catalyzes the formation of piRNA 5' ends. Mili mutants derepress LINE-1 (L1) and intracisternal A particle and lose DNA methylation of L1 elements, demonstrating an evolutionarily conserved role for PIWI proteins in transposon suppression.     

A survey of gastro-intestinal parasitic infection in domestic and wild birds in Chittagong and Greater Sylhet,Bangladesh

A survey of gastrointestinal parasitic infection as determined by faecal examination was conducted among domestic and wild birds in Bangladesh. Birds were sampled from households, wet markets and wetlands in Chittagong and Greater Sylhet districts during April 2012 to February 2013. Mist nets were used to catch resident wild and migratory birds. The overall prevalence of parasitic infection ranged among locations from 25 to 55% in indigenous domestic ducks (live bird samples = 304), 20% in resident wild birds (environmental faecal samples = 40) and 40% in migratory birds (live bird samples = 35). The prevalence of parasitic infection was significantly higher in indigenous domestic ducks collected during summer (39%) than winter (22%) (p = 0.04). In domestic indigenous ducks and Muscovy ducks, both single and multiple types of parasitic infections were found. However, other domestic birds and wild birds often had a single type of parasitic infection. Ascaridia spp. with an average egg load of 50–900, was commonly detected in faecal samples of domestic and wild birds in this study. Other identified parasites were Capillaria spp. and Heterakis spp. both in domestic and wild birds. Improvement of biosecurity measures for household duck farms through educating and motivating household farmers could help mitigate the effects of parasitic infection on production.     

Use of therapeutic plasmapheresis in a case of canine immune-mediated hemolytic anemia

Objective – To investigate the clinical application and potential utility of plasmapheresis in canine immune-mediated hemolytic anemia.
Case Summary – A 7-year-old spayed female Maltese diagnosed with immune-mediated hemolytic anemia was initially treated with prednisone, cyclosporine, and received multiple transfusions of packed RBC. Because of the progression of clinical signs despite traditional medical therapy, plasmapheresis was initiated. Plasma immunoglobulin G and immunoglobulin M levels were measured before, during, and after treatment to help determine if there had been a significant decrease in immunoglobulin levels with plasmapheresis. Plasmapheresis was successfully performed over a 2.5-hour period in this dog with minimal complications. Hypocalcemia was identified as a known complication of circuit anticoagulation, and was corrected through calcium supplementation. Post-plasmapheresis there was a decrease in immunoglobulin G and immunoglobulin M levels, and the patient showed clinical improvement. Following discharge the dog had no known complications of therapy, and had complete resolution of the anemia.
New or Unique Information Provided – Plasmapheresis was performed successfully with minimal complications. Because transfusion requirements appeared to be reduced, and the procedure was well tolerated, there may be a place for this modality in severe cases to act as a bridge until medical therapy takes full effect. Because of the cost of performing this therapy, and the potential requirement for multiple treatments, it should be reserved for selected patients.     

Interactions Between Soil Erosion Processes and Fires: Implications for the Dynamics of Fertility Islands

Shrub encroachment in arid and semiarid rangelands, a worldwide phenomenon, results in a heterogeneous landscape characterized by a mosaic of nutrient-depleted barren soil bordered by nutrient-enriched shrubby areas known as “fertile islands.” Even though shrub encroachment is considered as a major contributor to rangeland degradation, little is known about mechanisms favoring the reversibility of the early stages of this process. Here we synthesize the interactions between fires and soil erosion processes, and the implications of these interactions for management of rangelands. The burning of shrub vegetation develops relatively high levels of soil hydrophobicity. This fire-induced water repellency was shown to enhance the soil erodibility in and around burned shrub patches. The fire-induced enhancement of local-scale soil erosion results from changes in the interparticle bonding forces between the soil grains, thus altering the way moisture is retained in the soil. It has been shown—with a number of wind-tunnel studies, field-scale manipulative experiments, microtopographic measurements, and isotopic tracer studies—how the fire-erosion interactions affect the dynamics of fertility islands. Further we propose a new conceptual model of resource “island” dynamics that explains some of the findings previously reported in the literature on the interactions between aeolian processes and arid-land vegetation. In particular, we highlight the ability of fires to enhance the erodibility of nutrient-rich soils accumulated under the shrubs favoring the redistribution of soil resources, thereby contributing to the reversibility of the early stages of shrub encroachment.     

Exogenous cholesterol prevents cryocapacitation-like changes,membrane fluidity,and enhances in vitro fertility in bubaline spermatozoa

A study was conducted to determine the optimum dosage of the exogenous cholesterol-loaded cyclodextrins (CLC) to get maximum cryoprotection for bubaline spermatozoa. In the present study, 120 × 10⁶ spermatozoa were incubated in 2, 3 and 4 mg of CLC as grouped as Gr II, III and IV, respectively, and sperm progressive motility, intracellular Ca²⁺, capacitation status by protein tyrosine phosphorylation (PTP) assay and zona binding per cent (ZBP) and cleavage rate (CR) of the cryopreserved buffalo spermatozoa by in vitro fertility assay were assessed in comparison with an untreated control group (Gr I). Results revealed that there was a significant (p < .05) linear decrease in percentage of sperm population with higher intracellular Ca²⁺ and percentage of sperm population with medium or high capacitated by PTP in CLC treated from 2 to 3 mg and then increased to 4 mg/120 × 10⁶ spermatozoa whereas sperm progressive motility, percentage of sperm population with low capacitated, ZBP and CR were increased significantly (p < .05) in sperm population treated from 2 to 3 mg CLC and then decreased to 4 mg/120 × 10⁶ spermatozoa. The study has clearly indicated that CLC at 3 mg/120 × 10⁶ spermatozoa has maximum beneficial effects in protection of sperm progressive motility, membrane fluidity (low intracellular Ca²⁺); prevention of cryocapacitation (low capacitation pattern in immunolocalization) and enhancement of in vitro ZBP and CR. Post-thaw motility of the CLC-treated sperm has shown positively significant (p < .05) correlation with sperm population with low intracellular Ca²⁺, low capacitated sperm population, ZBP and CR, whereas it was negatively (p < .05) correlated with sperm population with high intracellular Ca²⁺, medium or high capacitated sperm. The present study has revealed for the first time that incubation of spermatozoa with CLC of higher dose (>3 mg/120 × 10⁶ spermatozoa) had adverse effects on sperm cryopreservation, although incubation of sperm with 3 mg/120 million prior to processing had minimised the freezing–thawing-associated damages in bubaline species.     

Resistance to ETEC F4/F18–mediated piglet diarrhoea: opening the gene black box

Diarrhoea, a significant problem in pig rearing industry affecting pre- and post-weaning piglets is caused by enterotoxigenic Escherichia coli (ETEC). The ETEC are classified as per the fimbriae types which are responsible for bacterial attachment with enterocytes and release of toxins causing diarrhoea. However, genetic difference exists for susceptibility to ETEC infection in piglets. The different phenotypes found in pigs determine their (pigs’) susceptibility or resistance towards fimbrial subtypes/variants (F4ab, F4ac, F4ad and F18). Specific receptors are present on intestinal epithelium for attachment of these fimbriae, which do not express to same level in all animals. This differential expression is genetically determined and thus their genetic causes (may be putative candidate gene or mutations) render some animals resistant or susceptible to one or more fimbrial subtypes. Genetic linkage studies have revealed the mapping location of the receptor loci for the two most frequent variants F4ab and F4ac to SSC13q41 (i.e. q arm of 13th chromosome of Sus scrofa). Some SNPs have been identified in mucin gene family, transferring receptor gene, fucosyltransferase 1 gene and swine leucocyte antigen locus that are proposed to be linked mutations for resistance/susceptibility towards ETEC diarrhoea. However, owing to the variety of fimbrial types and subtypes, it would be difficult to identify a single causative mutation and the candidate loci may involve more number of genes/regions. In this review, we focus on the genetic mutations in genes involved in imparting resistance/susceptibility to F4 or F18 ETEC diarrhoea and possibilities to use them as marker for selection against susceptible animals.

     

Collaborative modelling to support forest management: Qualitative systems analysis at Lumut Mountain,Indonesia

Complex ecological and social processes in tropical forests imply that observations on any single element of the system do not provide an adequate basis for sound forest management. A collaborative modelling process engaging all relevant stakeholders led to a shared understanding of how to manage forests around Lumut Mountain, Pasir District, East Kalimantan. The model was developed by identifying forest management objectives, building a conceptual model using a causal loop diagram, and defining performance indicators. The model was then used to explore future scenarios to improve the well-being of local stakeholders while maintaining forest quality. Finally, roles needed to implement the chosen scenarios were defined and assigned to individual participants. This qualitative modelling process was found to be an effective way to assist the development of a collaborative action plan. The authors wish to acknowledge that this paper has been produced with financial support from Department for International Development of UK, the Asian Development Bank under RETA Grant 5812 and CIFOR. The views expressed contained herein are solely of the authors and do not necessarily reflect official views of the donors or of CIFOR. The authors would like to thank Richard Dudley and Bruce Campbell for their inputs to the paper.