Investigation of the Effect of Polyurethane Hybrid Composites on the Acoustic Performance of Reactive Silencers Using COMSOL

Background and aim:In the contemporary world, one of the factors that has attracted increasing attention is sound control.Flexible polyurethane, which are one of the favorite materials in sound insulation, can also achieve better properties by reinforcing natural fibers.The purpose of this study is to make a polyurethane hybrid composite with kenaf and rice husk, as well as a combination of kenaf /rice husk to reduce the noise of the reactive silence

Echinococcus felidis in hippopotamus, South Africa

Hydatid cysts of Echinococcus felidis are described from the hippopotamus (Hippopotamus amphibius) from Mpumalanga Province, South Africa. Among six hippopotami investigated, hepatic hydatids were found in three. The identification was based on mitochondrial and nuclear DNA sequences. In addition, the rostellar hook morphology was analysed. This is the first morphological description of the metacestode of E. felidis, and the first molecularly confirmed report of the intermediate host of E. felidis in South Africa. The definitive host of E. felidis in South Africa is the lion (Panthera leo).Peer reviewe

Unusual morphological adaptations and processes associated with viviparity in an epizoic dermapteran

Matrotrophic viviparity is a reproductive pattern in which offspring develop inside a female's body which provides gas exchange and nutrients necessary for development. Besides placental mammals, structural and physiological aspects of matrotrophic viviparity are poorly characterized. In insects, the majority of species is oviparous, i.e. lay eggs, and viviparous reproduction has been reported only in 11 out of 44 orders, including earwigs (Dermaptera). Among dermapterans, matrotrophic viviparity has been reported in two epizoic subgroups: Arixeniidae and Hemimeridae. Here, we provide morphological evidence for distinct adaptations for this mode of viviparity in embryonic and maternal tissues in a representative of the latter subgroup, Hemimerus talpoides. Our study reveals a novel mechanism of maternal contribution to embryonic development which operates during oogenesis and involves characteristic modification of endoplasmic reticulum cisternae. Conspicuous and apparently inactive para-crystalline stacks of the endoplasmic reticulum are deposited in the oocyte cytoplasm and become activated during early embryonic development. Our analyses indicate additionally that in Hemimerus, transformed follicular/ovarian cells (on the mother's side) and an evagination of the dorsal vessel (on the embryo's side) converge to form a cephalic vesicle, structure analogous to a placenta. The cellular architecture of this unusual "cephalic placenta" points to its participation in an exchange of low molecular weight substances between a mother and developing embryo

Selected parasites of silver kob (Argyrosomus inodorus) (Actinopterygii: Sciaenidae) from northern Namibia

The present study reports five metazoan parasites recorded from silver kob (Argyrosomus inodorus). Five fish were collected monthly (n=55) for 11 months in 2017–2018 (excluding July 2017) using conventional angling gear in Toscanini, Mile 108 and Henties Bay, northern Namibia. Fish were examined individually for ecto- and endo-parasites. Photomicrographs, drawings and measurements of parasites were made using a camera lucida and calibrated eyepiece of an Olympus (BX50) compound microscope and/or a Zeiss (Discovery V8) camera calibrated on a Leica dissecting microscope. Amongst species found, monogeneans including Diplectanum sciaenae van Beneden & Hesse, 1863, two species of Calceostoma van Beneden, 1858, one species of Sciaenacotyle Mamaev, 1989 and one acanthocephalan Corynosoma australe Johnston, 1937 were found and are reported here. This is the first study of parasites found from silver kob of the Atlantic Ocean. Silver kob has potential to be used as a mariculture species. In addition to mariculture, information obtained from this study may also be used as a baseline for stock structure and biological tagging. Significance: • Silver kob has potential to be used as a mariculture species. Information obtained from this study will therefore form awareness to future mariculture silver kob farmers in terms of parasites that can infest and infect silver kob, hence making it possible to apply specific prevention and control measures. In addition to mariculture, results obtained from this study may be used as a baseline for biological tagging for stock structure assessment using parasites

Domestic dogs present a human-induced threat to thick-tailed bushbabies (Otolemur crassicaudatus) in Northern South Africa.

No abstract available.The Margot Marsh Biodiversity Foundation, through the Primate Action Fund.http://primates.squarespace.com/african_primateshj2024Mammal Research InstituteZoology and EntomologyNon

Parasites of domestic and wild animals in South Africa. L. Ixodid ticks infesting horses and donkeys

The aim of the study was to determine the species spectrum of ixodid ticks that infest horses and donkeys in South Africa and to identify those species that act as vectors of disease to domestic livestock. Ticks were collected opportunistically from 391 horses countrywide by their owners or grooms, or by veterinary students and staff at the Faculty of Veterinary Science, University of Pretoria. Ticks were also collected from 76 donkeys in Limpopo Province, 2 in Gauteng Province and 1 in North West province. All the ticks were identified by means of a stereoscopic microscope. Horses were infested with 17 tick species, 72.1% with Rhipicephalus evertsi evertsi, 19.4% with Amblyomma hebraeum and 15.6% with Rhipicephalus decoloratus. Rhipicephalus evertsi evertsi was recovered from horses in all nine provinces of South Africa and R. decoloratus in eight provinces. Donkeys were infested with eight tick species, and 81.6% were infested with R. evertsi evertsi, 23.7% with A. hebraeum and 10.5% with R. decoloratus. Several tick species collected from the horses and donkeys are the vectors of economically important diseases of livestock. Rhipicephalus evertsi evertsi is the vector of Theileria equi, the causative organism of equine piroplasmosis. It also transmits Anaplasma marginale, the causative organism of anaplasmosis in cattle. Amblyomma hebraeum is the vector of Ehrlichia ruminantium, the causative organism of heartwater in cattle, sheep and goats, whereas R. decoloratus transmits Babesia bigemina, the causative organism of babesiosis in cattle.The Department of Science and Technology and National Research Foundation of South Africa (Grant No 101054).http://www.ojvr.orgam2017Veterinary Tropical Disease

Phylogenetic analyses of bat-associated bugs (Hemiptera: Cimicidae: Cimicinae and Cacodminae) indicate two new species close to Cimex lectularius

Abstract Background Bats are regarded as the primary (ancestral) hosts of bugs of the family Cimicidae. The historically and economically most important species in the family is the common bedbug (Cimex lectularius), because of its worldwide occurrence and association with humans. This molecular-phylogenetic study was initiated in order to expand the knowledge on the phylogeny of cimicid bugs of bats, by investigating samples from Hungary, Romania (representing central-eastern Europe) and two further countries (South Africa and Vietnam). Results Altogether 216 cimicid bugs were collected (73 Ci. lectularius, 133 Ci. pipistrelli, nine Cacodmus ignotus and one Ca. sparsilis). Members of the Cimex lectularius species group were found both in the environment of bats (only Myotis emarginatus, which is a cave/attic-dwelling species) and on three crevice-dwelling bat species (two pipistrelloid bats and M. bechsteinii). On the other hand, Ci. pipistrelli always occurred off-host (near M. myotis/blythii, which are cave/attic-dwelling species). In addition, two Cacodmus spp. were collected from Pipistrellus hesperidus. The morphological characters of these specimens are illustrated with high resolution pictures. Analysis of cytochrome c oxidase subunit 1 (cox1) sequences generated from 38 samples indicated relative genetic homogeneity of Ci. pipistrelli, while the Ci. lectularius group had two haplotypes (collected from pipistrelloid bats in Hungary and Vietnam) highly divergent from other members of this species group. These results were confirmed with molecular and phylogenetic analyses based on the internal transcribed spacer 2 (ITS2). Bat-associated bugs morphologically identified as Ca. ignotus and Ca. sparsilis were different in their cox1, but identical in their ITS2 sequences. Conclusions Molecular evidence is provided here on the existence of two new genotypes, most likely new species, within the Ci. lectularius species group. The relevant specimens (unlike the others) were collected from pipistrelloid bats, therefore the association of Ci. lectularius with different bat host species (pipistrelloid vs myotine bats) should be evaluated further as a possible background factor of this genetic divergence. In addition, Ca. ignotus is reported for the first time in South Africa

Effects of relative replacement of different levels of dehulled soybean meal (DHSM) with fish meal on growth performance of adult Persian sturgeon, Acipenser persicus

The present study was designed and implemented to evaluate the effects of relative replacement of different levels of dehulled soybean meal (DHSM) instead of fish meal on growth performance of adult Persian sturgeon (Acipenser persicus). In this study, a total of eighty 4-year-old Persian sturgeons (Acipenser persicus), with an average weight of 3850 g were fed with 8 isonitrogenetic and isolipidic diets for 52 weeks. Experimental diets include different percentages of dehulled soybean meal include 0, 10, 15, 20% without amino acid, 15 and 20% replacement with lysine and methionine, and 15 and 20% replacement with lysine and methionine and L-carnitine supplement (DHSM0, DHSM10, DHSM15, DHSM20, DHSM20+AA, DHSM15+AA, DHSM20+AA+L.car. DHSM15+ AA+L.car.). After 52 weeks, no significant difference was observed between weight gain (WG), specific growth rate (SGR), LX and PV in different treatments. The protein efficiency ratio and feed efficiency (FE) in DHSM0 was significantly higher than that of DHSM20+AA and DHSM15+AA. Hepatosotic index of fish in DHSM0, DHSM10, DHSM15, DHSM20 + AA+L.car. DHSM30 + AA+L.car. was significantly higher than that in DHSM30 + AA. Gonadosomatic index exhibited alterations under the influence of the diet.  Effect of diets containing dehulled soybean meal with L-carnitine supplement on the reproductive system of female fish was significant and positive. The somatic growth in female Persian sturgeon was higher than that of males. However, their gonadic growth and stages of sexual maturity were significantly lower than that in males. The highest sexual maturity index of male fish was observed in DHSM15 + AA+L.car diet, so that at the end of the rearing period, 75% of fish were in stage IV of sexual maturity and 25% in stage III-IV. Addition of L-carnitine and essential amino acid supplement such as lysine and methionine to the diet containing soybean meal displayed a positive effect on the growth and reproductive indicators in the functional diet of Persian sturgeon and probably can improve significantly the production of Persian sturgeon fry

Reappraisal of Hydatigera taeniaeformis (Batsch, 1786) (Cestoda: Taeniidae) sensu lato with description of Hydatigera kamiyai n. sp.

The common cat tapeworm Hydatigera taeniaeformis is a complex of three morphologically cryptic entities, which can be differentiated genetically. To clarify the biogeography and the host spectrum of the cryptic lineages, 150 specimens of H. taeniaeformis in various definitive and intermediate hosts from Eurasia, Africa and Australia were identified with DNA barcoding using partial mitochondrial cytochrome c oxidase subunit 1 gene sequences and compared with previously published data. Additional phylogenetic analyses of selected isolates were performed using nuclear DNA and mitochondrial genome sequences. Based on molecular data and morphological analysis, Hydatigera kamiyai n. sp. Iwaki is proposed for a cryptic lineage, which is predominantly northern Eurasian and uses mainly arvicoline rodents (voles) and mice of the genus Apodemus as intermediate hosts. Hydatigera taeniaeformis sensu stricto (s.s.) is restricted to murine rodents (rats and mice) as intermediate hosts. It probably originates from Asia but has spread worldwide. Despite remarkable genetic divergence between H. taeniaeformis s.s. and H. kamiyai, interspecific morphological differences are evident only in dimensions of rostellar hooks. The third cryptic lineage is closely related to H. kamiyai, but its taxonomic status remains unresolved due to limited morphological, molecular, biogeographical and ecological data. This Hydatigera sp. is confined to the Mediterranean and its intermediate hosts are unknown. Further studies are needed to classify Hydatigera sp. either as a distinct species or a variant of H. kamiyai. According to previously published limited data, all three entities occur in the Americas, probably due to human-mediated introductions