Bifurcations and chaos control in a discrete Rosenzweig-Macarthur prey-predator model.

In this paper, we explore the local dynamics, chaos, and bifurcations of a discrete Rosenzweig-Macarthur prey-predator model. More specifically, we explore local dynamical characteristics at equilibrium solutions of the discrete model. The existence of bifurcations at equilibrium solutions is also studied, and that at semitrivial and trivial equilibrium solutions, the model does not undergo flip bifurcation, but at positive equilibrium solutions, it undergoes flip and Neimark-Sacker bifurcations when parameters go through certain curves. Fold bifurcation does not exist at positive equilibrium, and we have studied these bifurcations by the center manifold theorem and bifurcation theory. We also studied chaos by the feedback control method. The theoretical results are confirmed numerically.

Prevalence of gastrointestinal parasitic infection in cows and buffaloes in Lower Dir, Khyber Pakhtunkhwa, Pakistan

Abstract Gastrointestinal (GI) Parasitic infection is a hot issue for cattle management. There is variation of GI parasites effects in sex, age of cattle, drinking water condition, nutrition, and severity of infection. Studies on prevalence of GI parasites among cattle population in Dir Lower are lacking. A total of 40 farms were selected randomly in six tehsil namely Tehsil Adenzai, Tehsil Timergara, Tehsil Balambat, Tehsil Munda ,Tehsil Lalqala, Tehsil Khall. Freshly cattle fecal samples were collected randomly from the selected farms during March 2018 till December 2018. Out of 314 buffaloes and cattle examined 58.59% (184/314) were positive for eggs, cyst/oocyst of one or more species of GI Parasites. The prevalence of parasitic infection was higher in Buffaloes 63.55% (75/118) as compared to Cow 55.61% (109/196) but the difference was not significant (p>0.05) Entamoeba,spp, Moniezia spp, Haemonchus spp and Coccidian spp were found in this study. The non-treated animals indicated the highest percentage of infection in cow 57.71% (101/175) and buffalo 68.13% (62/91).GI parasite prevalence in female animal were higher female cow 62.58% (87/139) and female buffalo 77.33% (58/75) as compared to male. But the difference is non-significant (p> 0.05) Yearling calves had the lower rate of GI parasitic infection than adults. Future investigations are necessary to evaluate the economic loss due to GI parasites in cattles.

Resumo A infecção gastrointestinal (GI) parasitária é um assunto importante para o manejo do gado. Existem variações nos efeitos dos parasitas GI quanto a sexo, idade do gado, condição da água potável, nutrição e gravidade da infecção. Faltam estudos sobre a prevalência de parasitas GI entre a população de gado em Lower Dir. Um total de 40 fazendas foi selecionado aleatoriamente em seis tehsil, nomeadamente Tehsil Adenzai, Tehsil Timergara, Tehsil Balambat, Tehsil Munda, Tehsil Lalqala, Tehsil Khall. Amostras fecais de gado fresco foram coletadas aleatoriamente das fazendas selecionadas de março de 2018 até dezembro de 2018. Dos 314 búfalos e bovinos examinados, 58,59% (184/314) foram positivos para ovos, cisto/oocisto de uma ou mais espécies de parasitas GI. A prevalência de infecção parasitária foi maior em Buffaloes 63,55% (75/118) em comparação com vaca 55,61% (109/196), mas a diferença não foi significativa (p > 0,05). Entamoeba spp, Moniezia spp, Haemonchus spp e Coccidian spp foram encontrados neste estudo. Os animais não tratados indicaram a maior porcentagem de infecção em vacas 57,71% (101/175) e búfalos 68,13% (62/91). A prevalência do parasita GI em fêmeas foi maior em vacas fêmeas 62,58% (87/139) e búfalas 77,33% (58/75) em comparação ao masculino. Mas a diferença não é significativa (p > 0,05). A modelagem linear geral mostrou que o tratamento do animal estava significativamente relacionado com a prevalência de parasitas GI. Bezerros de um ano tiveram a maior taxa de infecção parasitária gastrointestinal. Futuras investigações são necessárias para avaliar a perda econômica devido aos parasitas GI em bovinos.

Distribution, screening and biochemical characterization of indigenous microalgae for bio-mass and bio-energy production potential from three districts of Pakistan.

Trend of biofuel production from microalgal triacylglycerols is enhancing, because this substrate is a good sustainable and advantageous alternative to oil and gas fuel. In the present study, indigenous micro algal isolates were screened from water (n=30) and soil (n=30) samples collected from three districts of Punjab, Pakistan to evaluate their biofuel production potential. The samples were inoculated on BG - 11 agar medium plates by incubating at room temperature of 25°C providing 1000 lux for 16h light cycle followed by 8h of dark cycle for 15 d. Water samples were found to be rich in microalgae and 65.33% microalgae (49 isolates) were isolated from Faisalabad district. On the basis of microscopic morphology microalgal isolates (n=180) were selected and subjected to lipid detection by Nile red staining assay. Nile red positive isolates (n=23) were processed for biochemical (lipid, protein and carbohydrates) characterization. AIN63 isolate showed higher lipids (17.4%) content as detected by micro vanillin assay. Algal isolate AIN128 showed best protein contents (42.91%) detected by Bradford assay and AIN172 isolate showed higher carbohydrate contents (73.83%) as detected by anthrone assay. The selected algal isolates were also analyzed by Fourier transform infrared (FTIR) spectroscopy for confirmation of carbohydrate, protein and lipid analysis. These indigenous algae have the potential for in-vitro biofuel production from agricultural waste.

Prevalence of gastrointestinal parasitic infection in cows and buffaloes in Lower Dir, Khyber Pakhtunkhwa, Pakistan.

Gastrointestinal (GI) Parasitic infection is a hot issue for cattle management. There is variation of GI parasites effects in sex, age of cattle, drinking water condition, nutrition, and severity of infection. Studies on prevalence of GI parasites among cattle population in Dir Lower are lacking. A total of 40 farms were selected randomly in six tehsil namely Tehsil Adenzai, Tehsil Timergara, Tehsil Balambat, Tehsil Munda ,Tehsil Lalqala, Tehsil Khall. Freshly cattle fecal samples were collected randomly from the selected farms during March 2018 till December 2018. Out of 314 buffaloes and cattle examined 58.59% (184/314) were positive for eggs, cyst/oocyst of one or more species of GI Parasites. The prevalence of parasitic infection was higher in Buffaloes 63.55% (75/118) as compared to Cow 55.61% (109/196) but the difference was not significant (p>0.05) Entamoeba,spp, Moniezia spp, Haemonchus spp and Coccidian spp were found in this study. The non-treated animals indicated the highest percentage of infection in cow 57.71% (101/175) and buffalo 68.13% (62/91).GI parasite prevalence in female animal were higher female cow 62.58% (87/139) and female buffalo 77.33% (58/75) as compared to male. But the difference is non-significant (p> 0.05) Yearling calves had the lower rate of GI parasitic infection than adults. Future investigations are necessary to evaluate the economic loss due to GI parasites in cattle's.

Assessment of ecto and endo parasites of Schizothorax plagiostomus inhabiting river Panjkora, Khyber Pakhtunkhwa, Pakistan / Avaliação de ecto e endoparasitas de Schizothorax plagiostomus habitantes do rio Panjkora, Khyber Pakhtunkhwa, Paquistão

Abstract Fish provides main source of high quality protein to more than one billion people in the world. Fish parasites directly affect the productivity of fish and indirectly on human health. This research was aimed to assess the helminth parasites in Schizothorax plagiostomus (the snow trout) from river Panjkora, KP, Pakistan. A total of 88 fish samples (n= 88) were collected from the upper, middle and lower regions of the river through cast nets, hand nets and hooks. All the collected fish samples were examined in the Parasitology Laboratory, Department of Zoology, University of Malakand for helminth parasites during July 2018 to February 2019.Among these fishes nematodes, trematodes, cestodes and acanthocephalan were isolated and identified. Overall prevalence of the fish parasites was 60.22% (53/88). The intensity of the parasite was observed from 1.7% to 4.61%. Highest prevalence was reported in summer season 86.36% while lowest in the winter season 36.36%. This study shows that summer season affects the fish business and result in poor quality fish meat with risk of zoonotic diseases. Adults were highly infected 82.25% while no infection was found in juvenile specimens. Female fish samples had higher prevalence 68.22% than males 48.22%. Fishes of the lower reaches had highest prevalence 60.22% than the upper reaches 40.0%. Fish samples with maximum length and weight were highly 76.92% infected than small sized fish with low body weight. Present study addresses that Rhabdochona schizothoracis in the intestine and Diplozoon paradoxum in gills of snow trout fish has a long term relationship and call as a natural infection in cyprinids and it is zoonotic threat to human.

Resumo O peixe é a principal fonte de proteína de alta qualidade para mais de um bilhão de pessoas no mundo. Contudo, parasitas afetam diretamente a produtividade de peixes e, indiretamente, a saúde humana. Esta pesquisa teve como objetivo avaliar os parasitas helmintos em Schizothorax plagiostomus (truta da neve) do rio Panjkora, Khyber Pakhtunkhwa, Paquistão. Foram coletadas 88 amostras de peixes (n = 88) dos trechos alto, médio e baixo do rio por meio de redes de arrasto, redes de mão e varas de pesca. Todas as amostras de peixes coletadas foram examinadas no Laboratório de Parasitologia do Departamento de Zoologia, da Universidade de Malakand, quanto a parasitas helmintos durante o período de julho de 2018 a fevereiro de 2019. Entre esses peixes, nematódeos, trematódeos, cestóideos e acantocéfalos foram isolados e identificados. A prevalência geral de parasitas de peixes foi de 60,22% (53/88). A intensidade do parasita foi observada de 1,7 a 4,61%. A maior prevalência (86,36%) foi relatada no verão, enquanto a menor (36,36%), no inverno. Este estudo mostra que a temporada de verão afeta o ramo da pesca e resulta em carne de baixa qualidade, com risco de doenças zoonóticas. Os adultos foram altamente infectados (82,25%), enquanto nenhuma infecção foi encontrada em jovens. As amostras de peixes do sexo feminino apresentaram maior prevalência (68,22%) do que as do sexo masculino (48,22%). Os peixes coletados no trecho baixo do rio tiveram maior prevalência (60,22%) do que os do trecho alto (40%). Amostras de peixes com comprimento e peso máximos foram altamente infectadas (76,92%) do que peixes de pequeno porte e baixo peso corporal. O presente estudo aborda que Rhabdochona schizothoracis no intestino e Diplozoon paradoxum em brânquias de peixes de truta da neve possuem uma estreita relação que causa uma infecção natural em ciprinídeos, sendo uma ameaça zoonótica ao ser humano.

Evaluation of ecto and endo parasitic fauna of Schizothorax plagiostomus inhabitants of river Swat, Khyber PakhtunKhwa, Pakistan / Avaliação da fauna ecto e endoparasitária de Schizothorax plagiostomus habitantes do rio Swat, Khyber Pakhtunkhwa, Paquistão

Abstract Fish is consumed as a rich and cheaper source of white meat and proteins all over the world. Fish farming is the leading source of income generation throughout the world. The present research study was conducted with aims to investigate the ecto and endo parasitic fauna of S. plagiostomus (snow trout) in River Swat. A total of 96 fish samples were collected on monthly basis from July-2018 to February-2019, from upper, middle and lower reaches. Fish samples were collected with the help of cast net, hand net and fishing rods. Local fishermen and experts help were also sought out for fish collection. 61 out of 96 fishes were found infected by helminth parasites. The total prevalence and intensity of 63.54% and 2.90 was observed respectively during data analysis. Highest monthly prevalence of 83.33% was recorded during July and August, while lowest prevalence of 33.33% was noted during February. Five species of helminths parasites were detected from S. plagiostomus, of which two were trematodes (Rhabdochona shizothoracis and Rhabdochona species), one species of Monogenia (Diplozoon paraddoxum), one species of Cestodes (Nippotaenia species), and one species of Acanthocephalan (Neoechynorhynchus devdevi). Highest parasite wise prevalence, intensity and relative density of 21.87%, 4.09 and 0.895 was noted for R. schizothoracis while the lowest prevalence, intensity and relative density of 4.16%, 1.25 and 0.052 was noted for N. devdevi. Highest infection of 76.08% was observed in adults host while lowest, 40% infestation rate was observed in young fish samples. 73.68% prevalence was observed in female hosts while only 56.90% prevalence was observed in male individuals. Higher infection (83.33%) was noticed during summer season, while lowest infection (44.44%) was observed during winter season. Similarly 71.79% fishes were found infected that were collected from lower reaches of the River Swat than the fish samples collected from upper reaches (52%).

Resumo O peixe é consumido mundialmente por ser uma fonte rica e barata de carne branca e proteínas. A piscicultura é a principal fonte de geração de renda em todo o mundo. O presente estudo foi conduzido com o objetivo de investigar a fauna ecto e endoparasitária de S. plagiostomus (truta da neve) no rio Swat. Foram coletadas mensalmente 96 amostras de peixes, no período de julho de 2018 a fevereiro de 2019, nos trechos alto, médio e baixo com auxílio de redes de arrasto, redes de mão e varas de pesca. Pescadores locais e especialistas também ajudaram na coleta de peixes. Dos 96 peixes encontrados, 61 estavam infectados por parasitas helmintos. A prevalência de 63,54% e a intensidade total de 2,90 foram observadas durante a análise dos dados. A maior prevalência mensal de 83,33% foi registrada nos meses de julho e agosto, enquanto a menor, de 33,33%, em fevereiro. Cinco espécies de parasitas helmintos foram detectadas de S. plagiostomus, dos quais dois eram trematódeos (espécies Rhabdochona shizothoracis e Rhabdochona), uma espécie de monogenia (Diplozoon paradoxum), uma espécie de cestóideos (espécie Nippotaenia) e uma espécie de acantocéfalo (Neoechynorhynchus devdevi). As maiores prevalências de parasitas (21,87%), intensidade (4,09) e densidade relativa (0,895) foram observadas em R. schizothoracis, enquanto as menores prevalências de parasitas (4,16%), intensidade (1,25) e densidade relativa (0,052), em N. devdevi. A infecção mais alta (76,08%) foi constatada em adultos hospedeiros, ao passo que a taxa de infestação mais baixa (40%) foi encontrada em amostras de peixes jovens. A prevalência de 73,68% foi verificada em hospedeiros do sexo feminino, enquanto a de 56,90%, em indivíduos do sexo masculino. Maior infecção (83,33%) foi observada durante a temporada de verão, e a menor infecção (44,44%), durante o inverno. Da mesma forma, 71,79% dos peixes encontrados infectados foram coletados no trecho baixo do rio Swat, enquanto 52%, no trecho alto.

Assessment of ecto and endo parasites of Schizothorax plagiostomus inhabiting river Panjkora, Khyber Pakhtunkhwa, Pakistan.

Fish provides main source of high quality protein to more than one billion people in the world. Fish parasites directly affect the productivity of fish and indirectly on human health. This research was aimed to assess the helminth parasites in Schizothorax plagiostomus (the snow trout) from river Panjkora, KP, Pakistan. A total of 88 fish samples (n= 88) were collected from the upper, middle and lower regions of the river through cast nets, hand nets and hooks. All the collected fish samples were examined in the Parasitology Laboratory, Department of Zoology, University of Malakand for helminth parasites during July 2018 to February 2019.Among these fishes nematodes, trematodes, cestodes and acanthocephalan were isolated and identified. Overall prevalence of the fish parasites was 60.22% (53/88). The intensity of the parasite was observed from 1.7% to 4.61%. Highest prevalence was reported in summer season 86.36% while lowest in the winter season 36.36%. This study shows that summer season affects the fish business and result in poor quality fish meat with risk of zoonotic diseases. Adults were highly infected 82.25% while no infection was found in juvenile specimens. Female fish samples had higher prevalence 68.22% than males 48.22%. Fishes of the lower reaches had highest prevalence 60.22% than the upper reaches 40.0%. Fish samples with maximum length and weight were highly 76.92% infected than small sized fish with low body weight. Present study addresses that Rhabdochona schizothoracis in the intestine and Diplozoon paradoxum in gills of snow trout fish has a long term relationship and call as a natural infection in cyprinids and it is zoonotic threat to human.

Evaluation of ecto and endo parasitic fauna of Schizothorax plagiostomus inhabitants of river Swat, Khyber PakhtunKhwa, Pakistan.

Fish is consumed as a rich and cheaper source of white meat and proteins all over the world. Fish farming is the leading source of income generation throughout the world. The present research study was conducted with aims to investigate the ecto and endo parasitic fauna of S. plagiostomus (snow trout) in River Swat. A total of 96 fish samples were collected on monthly basis from July-2018 to February-2019, from upper, middle and lower reaches. Fish samples were collected with the help of cast net, hand net and fishing rods. Local fishermen and experts help were also sought out for fish collection. 61 out of 96 fishes were found infected by helminth parasites. The total prevalence and intensity of 63.54% and 2.90 was observed respectively during data analysis. Highest monthly prevalence of 83.33% was recorded during July and August, while lowest prevalence of 33.33% was noted during February. Five species of helminths parasites were detected from S. plagiostomus, of which two were trematodes (Rhabdochona shizothoracis and Rhabdochona species), one species of Monogenia (Diplozoon paraddoxum), one species of Cestodes (Nippotaenia species), and one species of Acanthocephalan (Neoechynorhynchus devdevi). Highest parasite wise prevalence, intensity and relative density of 21.87%, 4.09 and 0.895 was noted for R. schizothoracis while the lowest prevalence, intensity and relative density of 4.16%, 1.25 and 0.052 was noted for N. devdevi. Highest infection of 76.08% was observed in adults host while lowest, 40% infestation rate was observed in young fish samples. 73.68% prevalence was observed in female hosts while only 56.90% prevalence was observed in male individuals. Higher infection (83.33%) was noticed during summer season, while lowest infection (44.44%) was observed during winter season. Similarly 71.79% fishes were found infected that were collected from lower reaches of the River Swat than the fish samples collected from upper reaches (52%).

Glycoamino Acid Analogues of the Thomsen-Friedenreich Tumor-Associated Carbohydrate Antigen: Synthesis and Evaluation of Novel Antiproliferative Factor Glycopeptides.

Glycoamino acid analogues of the Thomsen-Friedenreich antigen disaccharide, where the 4' and 4″ hydroxyl groups were substituted with fluorine or hydrogen, were synthesized and incorporated into the asialylated antiproliferative factor (as-APF), a biologically active form of APF, a glycopeptide found in the urine of patients with interstitial cystitis. Various strategies were employed to incorporate the fluorine atom at the 4-positions of either the galactose or N-acetylgalactosamine unit of the disaccharide antigen, based on stereochemistry and reactivity. These glycopeptides were evaluated in antiproliferative assays on both primary normal bladder epithelial cells and T24 bladder carcinoma cells. Unlike many previously published substitutions to APF, mono-4'-fluorination of the GalNAc residue did not affect the activity, whereas fluoro-derivatives of the galactose 4″-position or both 4' and 4″ hydroxyls showed a reduced potency relative to the monosubstituted GalNAc derivative. A fourth compound where the 4″ position of galactose was deoxygenated showed a lower potency than the parent and monosubstituted compounds. These results suggest that specific substitutions in the sugar moieties in the APF can be tolerated, and the glycomimetic design of APF analogues can include fluorine in the GalNAc sugar of the disaccharide.

Antibody Prevalence and Risk Factors for Toxoplasma gondii Infection in Women from Multan, Pakistan.

Toxoplasma gondii infections are prevalent in humans and warm-blooded animals. Maternal infections during pregnancy may have devastating consequences for transplacentally infected neonates. This study was conducted to examine the seroprevalence of antibodies to T. gondii in pregnant women of childbearing age and determine risk factors associated with pregnancy history, pet ownership, social and cultural factors at Nishtar Hospital, Multan. Samples were collected from 403 women and examined using a commercially available enzyme-linked immunosorbent assay (ELISA). The overall prevalence of antibodies to T. gondii was 17.6% (71) in the 403 samples collected from women. Antibodies to T. gondii were present in 19.4% (45) of 232 pregnant women and 15.2% (26) of the samples from 171 non-pregnant women. This study identified miscarriage history, pet ownership, type of residence, marital status, source of drinking water and eating habits as significant (P < 0.05) risk factors associated with the presence of antibodies to T. gondii infection. Seroprevalence was not significantly different (P > 0.05) in women from different ethnic groups based upon lifestyle and culture.

Assessment of ecto and endo parasites of Schizothorax plagiostomus inhabiting river Panjkora, Khyber Pakhtunkhwa, Pakistan

Abstract Fish provides main source of high quality protein to more than one billion people in the world. Fish parasites directly affect the productivity of fish and indirectly on human health. This research was aimed to assess the helminth parasites in Schizothorax plagiostomus (the snow trout) from river Panjkora, KP, Pakistan. A total of 88 fish samples (n= 88) were collected from the upper, middle and lower regions of the river through cast nets, hand nets and hooks. All the collected fish samples were examined in the Parasitology Laboratory, Department of Zoology, University of Malakand for helminth parasites during July 2018 to February 2019.Among these fishes nematodes, trematodes, cestodes and acanthocephalan were isolated and identified. Overall prevalence of the fish parasites was 60.22% (53/88). The intensity of the parasite was observed from 1.7% to 4.61%. Highest prevalence was reported in summer season 86.36% while lowest in the winter season 36.36%. This study shows that summer season affects the fish business and result in poor quality fish meat with risk of zoonotic diseases. Adults were highly infected 82.25% while no infection was found in juvenile specimens. Female fish samples had higher prevalence 68.22% than males 48.22%. Fishes of the lower reaches had highest prevalence 60.22% than the upper reaches 40.0%. Fish samples with maximum length and weight were highly 76.92% infected than small sized fish with low body weight. Present study addresses that Rhabdochona schizothoracis in the intestine and Diplozoon paradoxum in gills of snow trout fish has a long term relationship and call as a natural infection in cyprinids and it is zoonotic threat to human.

Resumo O peixe é a principal fonte de proteína de alta qualidade para mais de um bilhão de pessoas no mundo. Contudo, parasitas afetam diretamente a produtividade de peixes e, indiretamente, a saúde humana. Esta pesquisa teve como objetivo avaliar os parasitas helmintos em Schizothorax plagiostomus (truta da neve) do rio Panjkora, Khyber Pakhtunkhwa, Paquistão. Foram coletadas 88 amostras de peixes (n = 88) dos trechos alto, médio e baixo do rio por meio de redes de arrasto, redes de mão e varas de pesca. Todas as amostras de peixes coletadas foram examinadas no Laboratório de Parasitologia do Departamento de Zoologia, da Universidade de Malakand, quanto a parasitas helmintos durante o período de julho de 2018 a fevereiro de 2019. Entre esses peixes, nematódeos, trematódeos, cestóideos e acantocéfalos foram isolados e identificados. A prevalência geral de parasitas de peixes foi de 60,22% (53/88). A intensidade do parasita foi observada de 1,7 a 4,61%. A maior prevalência (86,36%) foi relatada no verão, enquanto a menor (36,36%), no inverno. Este estudo mostra que a temporada de verão afeta o ramo da pesca e resulta em carne de baixa qualidade, com risco de doenças zoonóticas. Os adultos foram altamente infectados (82,25%), enquanto nenhuma infecção foi encontrada em jovens. As amostras de peixes do sexo feminino apresentaram maior prevalência (68,22%) do que as do sexo masculino (48,22%). Os peixes coletados no trecho baixo do rio tiveram maior prevalência (60,22%) do que os do trecho alto (40%). Amostras de peixes com comprimento e peso máximos foram altamente infectadas (76,92%) do que peixes de pequeno porte e baixo peso corporal. O presente estudo aborda que Rhabdochona schizothoracis no intestino e Diplozoon paradoxum em brânquias de peixes de truta da neve possuem uma estreita relação que causa uma infecção natural em ciprinídeos, sendo uma ameaça zoonótica ao ser humano.

Evaluation of ecto and endo parasitic fauna of Schizothorax plagiostomus inhabitants of river Swat, Khyber PakhtunKhwa, Pakistan

Abstract Fish is consumed as a rich and cheaper source of white meat and proteins all over the world. Fish farming is the leading source of income generation throughout the world. The present research study was conducted with aims to investigate the ecto and endo parasitic fauna of S. plagiostomus (snow trout) in River Swat. A total of 96 fish samples were collected on monthly basis from July-2018 to February-2019, from upper, middle and lower reaches. Fish samples were collected with the help of cast net, hand net and fishing rods. Local fishermen and experts help were also sought out for fish collection. 61 out of 96 fishes were found infected by helminth parasites. The total prevalence and intensity of 63.54% and 2.90 was observed respectively during data analysis. Highest monthly prevalence of 83.33% was recorded during July and August, while lowest prevalence of 33.33% was noted during February. Five species of helminths parasites were detected from S. plagiostomus, of which two were trematodes (Rhabdochona shizothoracis and Rhabdochona species), one species of Monogenia (Diplozoon paraddoxum), one species of Cestodes (Nippotaenia species), and one species of Acanthocephalan (Neoechynorhynchus devdevi). Highest parasite wise prevalence, intensity and relative density of 21.87%, 4.09 and 0.895 was noted for R. schizothoracis while the lowest prevalence, intensity and relative density of 4.16%, 1.25 and 0.052 was noted for N. devdevi. Highest infection of 76.08% was observed in adults host while lowest, 40% infestation rate was observed in young fish samples. 73.68% prevalence was observed in female hosts while only 56.90% prevalence was observed in male individuals. Higher infection (83.33%) was noticed during summer season, while lowest infection (44.44%) was observed during winter season. Similarly 71.79% fishes were found infected that were collected from lower reaches of the River Swat than the fish samples collected from upper reaches (52%).

Resumo O peixe é consumido mundialmente por ser uma fonte rica e barata de carne branca e proteínas. A piscicultura é a principal fonte de geração de renda em todo o mundo. O presente estudo foi conduzido com o objetivo de investigar a fauna ecto e endoparasitária de S. plagiostomus (truta da neve) no rio Swat. Foram coletadas mensalmente 96 amostras de peixes, no período de julho de 2018 a fevereiro de 2019, nos trechos alto, médio e baixo com auxílio de redes de arrasto, redes de mão e varas de pesca. Pescadores locais e especialistas também ajudaram na coleta de peixes. Dos 96 peixes encontrados, 61 estavam infectados por parasitas helmintos. A prevalência de 63,54% e a intensidade total de 2,90 foram observadas durante a análise dos dados. A maior prevalência mensal de 83,33% foi registrada nos meses de julho e agosto, enquanto a menor, de 33,33%, em fevereiro. Cinco espécies de parasitas helmintos foram detectadas de S. plagiostomus, dos quais dois eram trematódeos (espécies Rhabdochona shizothoracis e Rhabdochona), uma espécie de monogenia (Diplozoon paradoxum), uma espécie de cestóideos (espécie Nippotaenia) e uma espécie de acantocéfalo (Neoechynorhynchus devdevi). As maiores prevalências de parasitas (21,87%), intensidade (4,09) e densidade relativa (0,895) foram observadas em R. schizothoracis, enquanto as menores prevalências de parasitas (4,16%), intensidade (1,25) e densidade relativa (0,052), em N. devdevi. A infecção mais alta (76,08%) foi constatada em adultos hospedeiros, ao passo que a taxa de infestação mais baixa (40%) foi encontrada em amostras de peixes jovens. A prevalência de 73,68% foi verificada em hospedeiros do sexo feminino, enquanto a de 56,90%, em indivíduos do sexo masculino. Maior infecção (83,33%) foi observada durante a temporada de verão, e a menor infecção (44,44%), durante o inverno. Da mesma forma, 71,79% dos peixes encontrados infectados foram coletados no trecho baixo do rio Swat, enquanto 52%, no trecho alto.

Structural basis of pathogen recognition by an integrated HMA domain in a plant NLR immune receptor.

Plants have evolved intracellular immune receptors to detect pathogen proteins known as effectors. How these immune receptors detect effectors remains poorly understood. Here we describe the structural basis for direct recognition of AVR-Pik, an effector from the rice blast pathogen, by the rice intracellular NLR immune receptor Pik. AVR-PikD binds a dimer of the Pikp-1 HMA integrated domain with nanomolar affinity. The crystal structure of the Pikp-HMA/AVR-PikD complex enabled design of mutations to alter protein interaction in yeast and in vitro, and perturb effector-mediated response both in a rice cultivar containing Pikp and upon expression of AVR-PikD and Pikp in the model plant Nicotiana benthamiana. These data reveal the molecular details of a recognition event, mediated by a novel integrated domain in an NLR, which initiates a plant immune response and resistance to rice blast disease. Such studies underpin novel opportunities for engineering disease resistance to plant pathogens in staple food crops.

Recognition of the Thomsen-Friedenreich pancarcinoma carbohydrate antigen by a lamprey variable lymphocyte receptor.

Variable lymphocyte receptors (VLRs) are leucine-rich repeat proteins that mediate adaptive immunity in jawless vertebrates. VLRs were recently shown to recognize glycans, such as the tumor-associated Thomsen-Friedenreich antigen (TFα; Galß1-3GalNAcα), with a selectivity rivaling or exceeding that of lectins and antibodies. To understand the basis for TFα recognition by one such VLR (VLRB.aGPA.23), we measured thermodynamic parameters for the binding interaction and determined the structure of the VLRB.aGPA.23-TFα complex to 2.2 Å resolution. In the structure, four tryptophan residues form a tight hydrophobic cage encasing the TFα disaccharide that completely excludes buried water molecules. This cage together with hydrogen bonding of sugar hydroxyls to polar side chains explains the exquisite selectivity of VLRB.aGPA.23. The topology of the glycan-binding site of VLRB.aGPA.23 differs markedly from those of lectins or antibodies, which typically consist of long, convex grooves for accommodating the oligosaccharide. Instead, the TFα disaccharide is sandwiched between a variable loop and the concave surface of the VLR formed by the ß-strands of the leucine-rich repeat modules. Longer oligosaccharides are predicted to extend perpendicularly across the ß-strands, requiring them to bend to match the concavity of the VLR solenoid.

A direct, efficient method for the preparation of siRNAs containing ribo-like North bicyclo[3.1.0]hexane pseudosugars.

An efficient method for the preparation of siRNAs modified with ribo-like North bicyclo[3.1.0]hexane pseudosugars is described. The combined use of 2'-O-(2-cyanoethoxymethyl) (CEM) and 2'-O-TBDMS protection was successfully employed for RNA synthesis with the added advantage that both groups were efficiently removed in a single step. The resulting North ribo-methanocarba-modified siRNAs are compatible with the intracellular RNAi machinery and can mediate specific degradation of target mRNA.

4'-C-methyl-2'-deoxyadenosine and 4'-C-ethyl-2'-deoxyadenosine inhibit HIV-1 replication.

It is important to develop new anti-HIV drugs that are effective against the existing drug-resistant mutants. Because the excision mechanism is an important pathway for resistance to nucleoside analogs, we are preparing analogs that retain a 3'-OH and can be extended after they are incorporated by the viral reverse transcriptase. We show that 4'-C-alkyl-deoxyadenosine (4'-C-alkyl-dA) compounds can be phosphorylated in cultured cells and can inhibit the replication of HIV-1 vectors: 4'-C-methyl- and 4'-C-ethyl-dA show both efficacy and selectivity against HIV-1. The compounds are also effective against viruses that replicate using reverse transcriptases (RTs) that carry nucleoside reverse transcriptase inhibitor resistance mutations, with the exception of the M184V mutant. Analysis of viral DNA synthesis in infected cells showed that viral DNA synthesis is blocked by the incorporation of either 4'-C-methyl- or 4'-C-ethyl-2'-deoxyadenosine. In vitro experiments with purified HIV-1 RT showed that 4'-C-methyl-2'-dATP can compete with dATP and that incorporation of the analog causes pausing in DNA synthesis. The 4'-C-ethyl compound also competes with dATP and shows a differential ability to block DNA synthesis on RNA and DNA templates. Experiments that measure the ability of the compounds to block DNA synthesis in infected cells suggest that this differential block to DNA synthesis also occurs in infected cells.

Using conformationally locked nucleosides to calibrate the anomeric effect: Implications for glycosyl bond stability.

Steric and electronic parameters such as the anomeric effect (AE) and gauche effect play significant roles in steering the North ⇆ South equilibrium of nucleosides in solution. Two isomeric oxa-bicyclo[3.1.0]hexane nucleosides that are conformationally locked in either the North or the South conformation of the pseudorotational cycle were designed to study the consequences of having the AE operational or not, independent of other parameters. The rigidity of the system allowed the orientation of the orbitals involved to be set in "fixed" relationships, either antiperiplanar where the AE is permanently "on", or gauche where the AE is impaired. The consequences of these two alternatives were subject to high-level calculations and measured experimentally by x-ray crystallography, hydrolytic stability of the glycosyl bond, and pKa values.