Elevated temperature affects growth and hemato‐biochemical parameters,inducing morphological abnormalities of erythrocytes in Nile tilapia Oreochromis niloticus     

SM Majharul Islam  Rabaya Sultana  Mohammad Imran  Mst. Fatema Tuj Jannat  Mohammad Ashaf‐Ud‐Doulah  Md. Fazle Rohani  Christopher Brown  Md. Shahjahan 《Aquaculture Research》2020,51(10):4361-4371

Temperature is considered as an important environmental factor, and the increasing water temperature resulting from global warming is a great concern. The present study was conducted to examine the effects of elevated water temperature on growth, hemato‐biochemical parameters in Nile tilapia, Oreochromis niloticus acclimatized to three temperatures (31°C, 34°C and 37°C) for 60 days. Additionally, erythrocytic cellular abnormalities (ECA) and erythrocytic nuclear abnormalities (ENA) tests were assayed using peripheral erythrocytes after exposure to the three temperatures. Fish were sacrificed on days 7, 15, 30 and 60 of exposure. Growth performances viz., weight gain, % weight gain and specific growth rate (SGR) showed decreasing tendency at 34°C but significantly declined at 37°C compared to 31°C. The abundance of haemoglobin (Hb) and red blood cells (RBCs) significantly decreased in response to temperature increases, while white blood cells (WBCs) displayed the opposite response. At days 7 and 15, blood glucose levels significantly increased in response to the temperature increase, while at days 30 and 60 glucose declined. Frequencies of ECA and ENA were significantly enhanced at the highest temperature throughout the experimental period. Dissolved oxygen decreased and free CO₂ increased significantly with increasing temperature throughout the study period. The present study revealed that temperatures higher than 34°C may be hazardous to O. niloticus.  相似文献   

Thyroid hormone‐induced swim bladder and eye maturation are transduced by IGF‐1 in zebrafish embryos     

Mohammad Habibur Rahman Molla  Md T. Hasan  Won J. Jang  Cesar D. Soria Diaz  Patrick Appenteng  Haliliy Marufchoni  Bushra Jahan  Christopher L. Brown 《Aquaculture Research》2019,50(11):3462-3470

Maternally derived thyroid hormones (THs) deposited in yolk promote fish embryogenesis and survival, and understanding early regulatory mechanisms could lead to improved seedstock production. We have tested the hypothesis that some thyroid actions may be mediated by insulin‐like growth factor I (IGF‐1), another promoter of embryo development. Differentiation and performance were assessed in embryos treated with THs in the presence or absence of an IGF‐1 receptor blocking peptide. Treatment with the TH triiodothyronine (T₃) promoted IGF‐1 gene expression at days 1 and 5, and advanced swim bladder and eye development, but blocking the IGF‐1 receptor eliminated the swim bladder and eye effects. Growth and survival at 1 week of age were impaired by the IGF‐1 receptor blocking peptide alone, but concurrent treatment with T₃ partially restored these indices. Our results confirm interaction of T₃ and IGF‐1 regulatory signalling in zebrafish embryogenesis and transduction by IGF‐1 of thyroid‐driven swim bladder and eye maturation.  相似文献   

Stock assessment and management implications of anchovy kilka (Clupeonella engrauliformis) in Iranian waters of the Caspian Sea     

Hasan Fazli  Chang Ik Zhang  Douglas Edward Hay  Chun-Woo Lee 《Fisheries Research》2009,100(2):103-108

Recent changes in sea level of the Caspian Sea and ecological impacts caused by the invasive ctenophore (Mnemiopsis leidyi) have altered the ecosystem. A consequence is the changes in the absolute and relative abundance of the commercially important anchovy kilka (Clupeonella engrauliformis) in Iranian waters. To adjust to this change more rigorous management of this fishery is required. This paper examines the maximum sustainable yield (MSY) and fishing intensity at MSY. The paper presents estimates of f_MSY, yield-per-recruit and spawning biomass-per-recruit under various harvest strategies of F_max, F_0.1 and F_40%. We propose a method for estimating acceptable biological catch (ABC) that accounts for large differences in the quality and quantity of information and available data. The MSY and f_MSY were estimated 44,652 mt (metric tons) and 18,609 vessel × nights (a unit of effort). The ABC was estimated at 2190 mt in 2004. In 2005, however, the catch of anchovy kilka was about 4300, over twice the estimated ABC. In 2008 (from January to October) the catch declined to 220 mt. The analyses indicate that overfishing, especially between 2005 and 2008, is the main reason of the collapse of anchovy kilka in the Caspian Sea.  相似文献   

Employment volatility in lagging and advanced regions: The Italian case     

Hasan Engin Duran  Ugo Fratesi 《Growth and change》2020,51(1):207-233

The presence of cycles characterizes all economic systems, but economic cycles have differentiated spatial impacts. Some regions have broader cycles with respect to the country, while others tend to be less responsive to shocks and hence have narrower cycles. Being exposed to broader cycles, that is, greater volatility, may increase the strain on a regional economic system. This paper investigates the different responsiveness to cyclical forces and volatility of regions in the long run. It does so by using quarterly employment data for the Nuts2 Italian regions over almost 40 years before and during the period 1978–2016. Explored in particular are the cross-regional variations in employment volatility and the reasons for the patterns observed, as well as whether they have changed the following different macroeconomic policy regimes. The paper identifies the break dates of different regimes, and these regime changes will be related to policy modifications, such as the implementation of the European Monetary Union. The determinants of this regional volatility appear to be quite stable, so that the changes in volatility are explained by how these determinants have changed overtime and how they are unevenly distributed in space. In particular, the lagging regions of the country suffer, in addition to lower production and income, from higher volatility due to a structure which is weaker and more unstable. Volatility can hence be an additional issue for lagging regions.  相似文献   

Effects of soil tillage,canola (Brassica napus L.) cultivars and planting date on canola yield,and oil and some biological and physical properties of soil     

Hossein Torabi  Hasan Ali Naghdibadi  Hossein Omidi  Heshmat Amirshekari 《Archives of Agronomy and Soil Science》2013,59(2):175-188

Determination of different agronomical properties including soil-related parameters for enhanced canola (Brassica napus L.) production can be of great significance. Hence, the objectives were to determine the effects of different tillage systems, canola cultivars and different planting dates on: (i) canola yield and oil, and (ii) soil moisture and microbial carbon (C) and nitrogen (N). Two field experiments were planned as split-plot experiments in three replicates. The main plots were different tillage systems including no-tillage (NT), minimum tillage (MT) and conventional tillage (CT), and the subplots were the combination of different canola cultivars (PF and Hyola 401) and different planting dates (PD): 8 and 23 September and 7 October. Soil moisture under CT and PF was significantly less than that of MT and NT, and Hyola 401, respectively. Carbon and N microbial biomass was the highest at NT and on the first PD. The tillage method and planting date also significantly affected canola yield, oil content and the amount, and the number of earthworms. We may conclude that although the amount of yield was the highest at CT, it may be more agronomically sustainable to plant canola under NT or MT earlier during the autumn growing season.  相似文献   

Seroprevalence of Coxiella burnetii antibodies in wild deer populations in eastern Australia     

L Voss  J Huaman  C Pacioni  A Tolpinrud  K Helbig  TG Carvalho  SM Firestone 《Australian veterinary journal》2023,101(3):106-114

Coxiella burnetii causes significant reproduction losses in livestock and the disease Q fever in humans. Transmission of C. burnetii is facilitated by the stability of the bacterium in the environment and the susceptibility of a variety of host species to infection. Consequently, inter-species transmission occurs frequently through either direct or indirect contact. Wildlife may represent reservoirs of C. burnetii and could therefore be a source of infection for domestic animals. Understanding the prevalence of C. burnetii infections at the wildlife-livestock interface is important for disease control. This study aimed to investigate the extent of C. burnetii exposure in wild deer in eastern Australia. Serum samples were obtained from 413 wild deer from seven regions in four eastern Australian states from 2017 to 2020. Antibodies were detected using a commercial Q fever antibody kit validated for ruminants. Seroprevalence of C. burnetii antibodies in deer was determined and true prevalence estimated, for each region. The overall seroprevalence of C. burnetii antibodies in wild deer was 3.4% (14 seropositive of 413 deer sampled) with true prevalence estimated to be 4.3% (95% credible interval: 0.6%, 10.9%). Seropositive deer were identified only in Queensland (7/108 seropositive) and northern New South Wales (7/120 seropositive). This geospatial distribution is consistent with seropositivity in other animal species and indicative of the level of C. burnetii in the environment. The low seroprevalence suggests that wild deer are unlikely to be a major reservoir species for C. burnetii in eastern Australia but may still be implicated in inter-species transmission cycles.  相似文献   

Insecticide resistance compromises the control of Aedes aegypti in Bangladesh     

Hasan Mohammad Al-Amin  Narayan Gyawali  Melissa Graham  Mohammad Shafiul Alam  Audrey Lenhart  Leon E Hugo  Gordana Rašić  Nigel W Beebe  Gregor J Devine 《Pest management science》2023,79(8):2846-2861

BACKGROUND

With no effective drugs or widely available vaccines, dengue control in Bangladesh is dependent on targeting the primary vector Aedes aegypti with insecticides and larval source management. Despite these interventions, the dengue burden is increasing in Bangladesh, and the country experienced its worst outbreak in 2019 with 101 354 hospitalized cases. This may be partially facilitated by the presence of intense insecticide resistance in vector populations. Here, we describe the intensity and mechanisms of resistance to insecticides commonly deployed against Ae. aegypti in Dhaka, Bangladesh.

RESULTS

Dhaka Ae. aegypti colonies exhibited high-intensity resistance to pyrethroids. Using CDC bottle assays, we recorded 2–24% mortality (recorded at 24 h) to permethrin and 48–94% mortality to deltamethrin, at 10× the diagnostic dose. Bioassays conducted using insecticide–synergist combinations suggested that metabolic mechanisms were contributing to pyrethroid resistance, specifically multi-function oxidases, esterases, and glutathione S-transferases. In addition, kdr alleles were detected, with a high frequency (78–98%) of homozygotes for the V1016G mutation. A large proportion (≤ 74%) of free-flying and resting mosquitoes from Dhaka colonies survived exposure to standard applications of pyrethroid aerosols in an experimental free-flight room. Although that exposure affected the immediate host-seeking behavior of Ae. aegypti, the effect was transient in surviving mosquitoes.

CONCLUSION

The intense resistance characterized in this study is likely compromising the operational effectiveness of pyrethroids against Ae. aegypti in Dhaka. Switching to alternative chemical classes may offer a medium-term solution, but ultimately a more sustainable and effective approach to controlling dengue vectors is required. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

Comparison of Whole Ovary Cryotreatments for Fertility Preservation          下载免费PDF全文

L Lotz  T Hauenstein  SM Nichols‐Burns  P Strissel  I Hoffmann  S Findeklee  R Dittrich  MW Beckmann  PG Oppelt 《Reproduction in domestic animals》2015,50(6):958-964

The goal of this study was to compare a traditional slow‐freeze method (TF) with an open unidirectional slow freeze cooling system (UF) for whole ovary cryopreservation. Therefore, whole pig ovaries were randomly assigned to (A) fresh control, (B) traditional slow freeze (TF) or (C) unidirectional slow freeze (UF). Ovaries were perfused with 10% DMSO in Krebs‐Ringer. For TF, whole ovaries were placed in specimen jars containing 10% DMSO and placed into a specialized container for freezing filled with propan‐2‐ol. For UF, whole ovaries were placed within a specially designed container containing 10% DMSO and transferred to a specialized freezing machine (CTE 920). Histological evaluation demonstrated intact morphology of follicles in all groups; however, an overall decrease of follicle numbers in TF (46%) and UF (50%) compared to fresh control. Live/dead assay indicated significantly lower populations of live cells in both TF (60%) and UF (58%) compared to fresh tissue (74%). TUNEL assay confirmed a difference in percentage of apoptotic follicles between fresh and TF, but there was no significant difference between fresh and UF. To improve the structural and functional integrity of whole ovaries, further investigation, especially into directional freezing, is needed. Whole ovary cryopreservation could provide opportunities for women facing fertility loss due to chemo‐ or radiotherapy treatment.  相似文献   

Antibacterial activity and cytotoxicity of extractives from Uvaria hamiltonii stem bark   总被引：2，自引：0，他引：2  

Asha KN  Chowdhury R  Hasan CM  Rashid MA 《Fitoterapia》2003,74(1-2):159-163

The extracts as well as piperolactum C, goniopedaline, 6beta-hydroxystigmasta-4,22-dien-3-one and a mixture of cis- and trans-4-hydroxymelleins obtained from Uvaria hamiltonii stem bark exhibited mild to moderate in vitro antibacterial activity. The results obtained were compared with a standard antibiotic, kanamycin. In a brine shrimp lethality bioassay the pet-ether, dichloromethane, methanol extracts and a major alkaloid, piperolactum C were found to exhibit mild to moderate cytotoxicity.  相似文献   

Über das Vorkommen von Blattlausarten(Aphidoidea) im türkischen Forst     

Dr. Hasan Çanakçioglu 《Journal of pest science》1972,45(10):152-154

Zusammenfassung Die Aphiden in den türkischen Forsten (114 Arten in 7 Familien) und deren Wirtspflanzen sowie ihre ö konomische Bedeutung sind in diesem Artikel zusammengestellt. Die wichtigsten Arten sind.Pineus orientalis (Dreyf.),P. pini (Macq.) (Adelgidae);Cinara cedri Mime.,C. palaestinensis H. R. Lamb. (Lachidae);Eriosoma lanuginosum (Hart.) (Pemphigidae);Phyllaphis fagi (L.) (Callaphidae) undAphis craccivora Koch (Aphididae).Weitere in den türkischen Wäldern verbreitete Blattlausarten können orts- und zeitweise von Bedeutung sein.

---

Summary The aphids of Turkish forests (114 species in 7 families), their host plants and economic importance are summarized. More important species are:Pineus orientalis (Dreyf.),P. pini (Macq.) (Adelgidae);Cinara cedri Mim.,C. palaestinensis H. R. Lamb. (Lachnidae);Eriosoma lanuginosum (Hart.) (Pemphigidae);Phyllaphis fagi (L.) (Callaphididae) andAphis craccivora Koch (Aphididae).The other aphids which are recorded in Turkish forest, in some extent are important species.

  相似文献