Bats of Cat Tien national park: diversity, echolocation and taxonomic remarks

Cat Tien National Park is a hotspot in Vietnam for biodiversity research and conservation. The park, with its extensive areas of primary forest, wetland habitats and large mammal populations, is known worldwide for its outstanding landscapes and biodiversity. Prior to 2007, several bat surveys were carried out in the park. However, data on the park’s bats is still limited and the status of previous records of a number of species is unclear. Between 2008 and 2015, the author conducted a series of bat surveys in the park with emphases on taxonomy and echolocation. Bats were captured using mist nets and four-bank harp traps. Echolocation calls were recorded from inside a flight tent and in natural habitats. Results from the surveys and a literature review indicated that Cat Tien National Park is currently known to be home to 47 bat species belonging to 22 genera and 7 families. Of these, 19 species belonging to 10 genera and 5 families were recorded during field surveys between 2008 and 2015. This paper provides the most recent review of bat species from Cat Tien National Park. Remarks on taxonomy and echolocation frequencies of species complexes are also given in order to assist further research, training, education, management and conservation

ĐÁNH GIÁ TÍNH ĐA DẠNG VÀ HIỆN TRẠNG CỦA CÁC LOÀI DƠI Ở KHU DỰ TRỮ SINH QUYỂN CÙ LAO CHÀM – HỘI AN

Cu Lao Cham-Hoi An Biosphere Reserve, which is commly known as Cu Lao Cham, is a well-known locality in Vietnam. It has received attention from national and international scientists and public communities. However, biodiversity of the biosphere is still poorly studied. In order to provide a confirmed database of bats from Cu Lao Cham, the author conducted two bat surveys with emphases on taxonomy and echolocation between May and August 2015. The survey results indicate that Cu Lao Cham is a home to 7 species belonging to 4 genera, 4 families, 2 suborders: Cynopterus horsfieldii, Rhinolophus affinis, R. pusillus, Hipposideros galeritus, H. grandis, H. pomona và Pipistrellus abramus. Of which, H. grandis is the most common species throughout the reserve. The species was recorded during the whole surveys and at almost all forest habitats. There is not sufficient evidence to confirm the occurrence of the five bat species, which was listed in a previously published literature (Hipposideros armiger, H. bicolor, H. larvatus, Pipistrellus ceylonicus và P. javanucus) in Cu Lao Cham. This paper provides a confirmed data on diversity and conservation status of bats of the reserve.Khu Dự trữ Sinh quyển Cù Lao Chàm-Hội An là một trong những địa danh nổi tiếng ở Việt Nam; đã và đang nhận được sự quan tâm của các nhà khoa học và công chúng ở trong và ngoài nước. Tuy nhiên, dẫn liệu về đa dạng sinh học của khu dự trữ sinh quyển này còn rất hạn chế. Nhằm góp phần khắc phục sự thiếu hụt dẫn liệu về các loài sinh vật ở những hệ sinh thái trên cạn của khu dự trữ sinh quyển, tác giả đã khảo sát thực địa, nghiên cứu đặc điểm hình thái phân loại và tiếng kêu siêu âm của các loài dơi trong năm 2015. Kết quả nghiên cứu đã ghi nhận được 7 loài thuộc 4 giống, 4 họ, 2 phân bộ: Cynopterus horsfieldii, Rhinolophus affinis, R. pusillus, Hipposideros galeritus, H. grandis, H. pomona và Pipistrellus abramus. Trong đó, Dơi nếp mũi xám lớn (H. grandis) là loài phổ biến nhất, bắt gặp trong suốt các đợt điều tra thực địa ở các sinh cảnh rừng khác nhau. Những loài còn lại chỉ gặp ở một vài sinh cảnh. Cá biệt, Dơi muỗi lông đen (Pipistrellus abramus) chỉ được ghi nhận ở một địa điểm căn cứ vào đặc điểm tiếng kêu siêu âm đặc trưng của loài. Không có bằng chứng về sự tồn tại của 5 loài dơi đã ghi nhận trước đây ở khu vực nghiên cứu: Hipposideros armiger, H. bicolor, H. larvatus, Pipistrellus ceylonicus và P. javanucus

Morphological and acoustic identification of Hipposiderids (Chiroptera: Hipposideridae) from Xuan Son national park, Northeastern Vietnam

Xuan Son National Park is a well known locality in Vietnam for its karst landscape and biodiversity values. The park contains a large number of caves, which are homes to 20 bat species belonging to 13 genera, four families. Of which, four species, viz. Aselliscus stoliczkanus, Hipposideros armiger, H. larvatus and H. pomona, belong to the family Hipposideridae. Prior to 2010, almost all bat researchs at the park focused on taxonomy. Between 2011 and 2015, the author conducted a series of field surveys with emphases on both taxonomy and echolocation of hipposiderids. External measurements of every captured bat were taken for taxonomic assessments. Echolocation calls were recorded from natural habitats while bats flying and different situations inside a flight-tent. Results from the surveys indicated that, within Xuan Son National Park, each hipposiderid species is clearly distinguishable from the remainders of the family Hipposideridae in both morphology and echolocation frequency. This paper provides acoustic and morphological diagnoses of hipposiderids for practical monitoring, further studies and conservation of hipposiderids at the park in the future

Analysis and Simulation of MRC Diversity Reception in Correlated Composite Nakagami-Lognormal Fading Channels

The physical meaning of the composite Nakagami-lognormal fading model is not well understood by many researchers using the model. The signal power transfer and transform at the interface between the global lognormal shadowing sub-channels and the local Nakagami multipath sub-channels in the presence of correlation between these diversity sub-channels is rather complex. This is the main reason why a thorough analysis or a simulation model is absent to date for the case of correlated composite Nakagami-lognormal diversity channels. This paper presents a novel technique for the estimation of the probability density function (PDF) of the signal-to-noise (SNR) at the output of a maximum ratio combining (MRC) receiver operating in correlated composite diversity fading channels. The PDF is estimated using the recently proposed two-point lossless moment generating function (MGF) matching technique and a closed-form expression for the bit-error rate (BER) for QPSK signal is consequently presented using the Gauss-Hermite polynomial approximation. The paper also presents the complex Monte-Carlo simulation model for the MRC reception and BER counting in correlated composite Nakagami-lognormal fading channels

Morphometric variation in the pusillus group of the genus Rhinolophus (Mammalia: Chiroptera: Rhinolophidae) in East Asia.

Based on 203 specimens belonging to the Rhinolophus "pusillus group" (Mammalia: Chiroptera: Rhinolophidae), univariate and multivariate morphometric analyses using 19 characters were performed to assess the confused species taxonomy. The results indicated that R. pusillus (including calidus, parcus, and szechuanus) in the continental region and Hainan Island of China and "R. cornutus" in Japan are morphologically divergent species. Rhinolophus cornutus should be further split into R. cornutus (including orii, pumilus, and miyakonis) in the main islands of Japan, the Amami and Okinawa Group of the central Ryukyu Archipelago, and Miyako Group of the southern Ryukyus; and R. perditus and R. imaizumii from the Yaeyama Group in the southern Ryukyus. Rhinolophus monoceros from Taiwan is morphologically more similar to species in Japan than to R. pusillus. In addition to R. pusillus, another form that is morphologically similar to species in Japan was recognized from Langzhong in Sichuan Province; this may represent an undescribed species, and further examination is necessary to determine its taxonomic status. Specimens from Guang'an in Sichuan Province, China, are also different from the others, and are characterized by the smallest skull size. Although further studies are required, these specimens were tentatively identified as R. subbadius

New records and morphological assessments of long-nosed fruit bats (chiroptera: pteropodidae: Macroglossus spp.) from Vietnam

Long-nosed fruit bat is a common name of the genus Macroglossus which comprises two species: Dagger-toothed long-nosed fruit bat (M. minimus) and Greater long-nosed fruit bat (M. sobrinus). These two species were rarely recorded from Vietnam or neighboring countries. Within Vietnam, M. minimus has been recorded only from two localities in southern Vietnam while M. sobrinus was known from all northern, central and southern regions of the country. Morphological features of these species in Vietnam were poorly documented in previous publications. With results from a rapid examination of all specimens and recently captured individuals, we here confirm that M. sobrinus is distinctively larger than M. minimus in all external and craniodental measurements. Two species are also distinguishable by their nostril shapes and mandible symphyses. This paper provides new distributional records of both M. sobrinus and M. minimus from Vietnam with remarks on their ecology and habitats.

KHẢ NĂNG ỨC CHẾ ĂN MÒN CỦA AMOXICILLIN TRÊN THÉP CÁC BON TRONG MÔI TRƯỜNG HCl 1 M

The corrosion inhibition of amoxicillin (AMO) on mild carbon steels in 1 M HCl acid solution was studied experimentally and with computational chemistry techniques. The inhibition efficiency increases with the concentration of AMO, reaching the maximal value (84.72%) at 100 mg·L–1 and 25°C. Several quantum chemical parameters were calculated based on the optimal configuration of AMO at the theoretical level of B3LYB/6-31+G(d,p). Molecular dynamics and Monte Carlo simulation were used to configure the most robust absorption configuration on the surface of Fe(110) and clarify the mechanism of the inhitition process. The results show that AMO is an effective corrosion inhibitor.Sự ức chế ăn mòn của amoxicillin (AMO) trên thép các bon nhẹ trong môi trường HCl 1 M đã được nghiên cứu bằng phương pháp thực nghiệm và hóa tính toán. Hiệu quả ức chế ăn mòn của AMO lên thép tăng lên khi tăng nồng độ AMO và đạt cực đại (84,72%) ở 25 °C và nồng độ AMO 100 mg·L–1. Một vài thông số hóa lượng tử được tính toán dựa trên cấu hình tối ưu của AMO ở mức ở mức lý thuyết B3LYP/6-31+G(d,p). Mô phỏng động lực học phân tử và mô phỏng Monte Carlo được ứng dụng để tìm cấu hình                               hấp phụ bền nhất của AMO trên bề mặt Fe(110) và làm rõ cơ chế của quá trình ức chế ăn mòn. Kết quả cho thấy AMO là một chất ức chế ăn mòn hiệu quả đối với thép các bon nhẹ trong dung dịch HCl 1 M

Quantifying the Covalent Functionalization of Black Phosphorus

A straightforward quantification method to consistently determine the overall functionalization degree of covalently modified two-dimensional (2D) black phosphorus (BP) by Raman spectroscopy has been carried out. Indeed, the successful reductive methylation of the BP lattice using sodium intercalation compounds and exhibiting different functionalization degrees has been demonstrated by 31P-magic angle spinning (MAS) NMR spectroscopy. Furthermore, the correlation of 31P-MAS NMR spectroscopy and statistical Raman spectroscopy (SRS) revealed the first method to determine the functionalization degree of BP solely by evaluating the intensities of distinct peaks in the Raman spectra of the covalently modified material, in a similar way to the widely employed ID/IG ratio of graphene research

New records of bats (Mammalia: Chiroptera) from Cu Lao Cham and Ly Son archipelagos, central Vietnam

Cu Lao Cham and Ly Son are two well-known archipelagos of Vietnam for their specular landscapes and varied ecosystems including forest, cave, and agriculture. However, their bat fauna has received little attention. Between July 2017 and August 2018, we conducted a series of mammal surveys with emphasis on bats of the two archipelagos. Bats were captured by mist nets and harp traps. Echolocation calls of microchiropteran species were recorded using the PCTape system then analysed by Selena software. With reference to all available literatures and specimens from the recent surveys, we obtained confirmed records of 9 bat species from Cu Lao Cham and 3 species from Ly Son. Of these, Megaderma spasma and Taphozous melanopogon are new to Cu Lao Cham while Rhinolophus macrotis is new to Ly Son. These three species were rarely recorded from other islands of Vietnam and also uncommon within Cu Lao Cham and Ly Son. These new records not only expand the known distributional range, but also provide worthwhile notes on a narrow geographical variation in morphology and echolocation of each species