scholarly journals Quantifying the Influence of Larval Density on Disease Transmission Indices in Culex quinquefasciatus, the Major African Vector of Filariasis

2019 ◽  
Vol 11 ◽  
pp. 117954331985602 ◽  
Author(s):  
Azubuike Christian Ukubuiwe ◽  
Chioma Cynthia Ojianwuna ◽  
Israel Kayode Olayemi ◽  
Francis Ofurum Arimoro ◽  
Innocent Chukwuemeka James Omalu ◽  
...  
Keyword(s):  
Culex Quinquefasciatus ◽  
Disease Transmission ◽  
Abiotic Factors ◽  
Larval Density ◽  
Field Trials ◽  
Negative Effects ◽  
Laboratory Findings ◽  
Factors Affecting ◽  
Adult Fitness ◽  
Larval Crowding

Larval crowding is one of the abiotic factors affecting biological fitness in mosquitoes. This study aims at elucidating, quantitatively, the influence of more larval crowding on aspects of fitness in Culex quinquefasciatus mosquito. To this end, day-old larvae of the species were reared in 4 density regimens equivalent to 1 larva in 1.25, 2.5, 5, and 10 mL of distilled water. Developmental indices, adult fitness indices, and accumulation and utilisation of teneral reserves for metamorphosis were determined at these density regimens. The results revealed varying significant negative effects of larval density on all fitness indices measured for the species. The study also revealed high utilisation of teneral reserves for metamorphosis at high larval densities. The information generated will be useful in making informed-decisions in allocating scare resources for vector control, although field trials are advocated to establish these laboratory findings.

scholarly journals Effects of Varying Photoperiodic Regimens on Critical Biological Fitness Traits of Culex quinquefasciatus (Diptera: Culicidae) Mosquito Vector

2018 ◽  
Vol 10 ◽  
pp. 117954331876791 ◽  
Author(s):  
Azubuike Christian Ukubuiwe ◽  
Israel Kayode Olayemi ◽  
Innocent Chukwuemeka James Omalu ◽  
Francis Ofurum Arimoro ◽  
Bulus Musa Baba ◽  
...  
Keyword(s):  
Culex Quinquefasciatus ◽  
Disease Transmission ◽  
Control Strategies ◽  
Adult Life ◽  
Adult Longevity ◽  
Mosquito Vector ◽  
Life Stages ◽  
Negative Effects ◽  
Life Traits ◽  
Faster Development

This study investigated the effects of varying photoperiodic conditions on critical life stages’ parameters of Culex quinquefasciatus. To this end, first larval stage was reared under different constant photoperiodic regimens: 0, 6 (short), 12 (equal), 13 (prevailing condition), and 18 and 24 (long) hours of light (hL). Duration of development, survivorship, emergence successes, adult longevity, caloric indices (CIs), and utilisation of teneral reserves for metamorphosis at each regimen were monitored. Analyses revealed significant negative effects of increasing photoperiod on all entomological variables measured. Short photo-phases elicited faster development times, increased life stages’ survivorship and number at emergence, adult longevity, and CI for all life stages while increasing teneral components for adult life traits. The information generated in this study is important in understanding the role played by photoperiod in disease transmission and for development of integrated vector control strategies based on environmental manipulation.

scholarly journals Opportunities and limits of controlled-environment plant phenotyping for climate response traits

2021 ◽  
Author(s):  
Anna Langstroff ◽  
Marc C. Heuermann ◽  
Andreas Stahl ◽  
Astrid Junker
Keyword(s):  
Crop Production ◽  
Field Trials ◽  
Plant Phenotyping ◽  
Controlled Environment ◽  
Climate Response ◽  
Negative Effects ◽  
Phenotypic Data ◽  
Non Invasive ◽  
Controlled Environments ◽  
Response Traits

AbstractRising temperatures and changing precipitation patterns will affect agricultural production substantially, exposing crops to extended and more intense periods of stress. Therefore, breeding of varieties adapted to the constantly changing conditions is pivotal to enable a quantitatively and qualitatively adequate crop production despite the negative effects of climate change. As it is not yet possible to select for adaptation to future climate scenarios in the field, simulations of future conditions in controlled-environment (CE) phenotyping facilities contribute to the understanding of the plant response to special stress conditions and help breeders to select ideal genotypes which cope with future conditions. CE phenotyping facilities enable the collection of traits that are not easy to measure under field conditions and the assessment of a plant‘s phenotype under repeatable, clearly defined environmental conditions using automated, non-invasive, high-throughput methods. However, extrapolation and translation of results obtained under controlled environments to field environments is ambiguous. This review outlines the opportunities and challenges of phenotyping approaches under controlled environments complementary to conventional field trials. It gives an overview on general principles and introduces existing phenotyping facilities that take up the challenge of obtaining reliable and robust phenotypic data on climate response traits to support breeding of climate-adapted crops.

scholarly journals Addressing the COVID-19 transmission in inner Brazil by a mathematical model

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. B. Almeida ◽  
T. N. Vilches ◽  
C. P. Ferreira ◽  
C. M. C. B. Fortaleza
Keyword(s):  
Mathematical Model ◽  
Disease Transmission ◽  
Abiotic Factors ◽  
Severe Pneumonia ◽  
Mitigation Strategies ◽  
Social Distancing ◽  
Control Disease ◽  
Set Up ◽  
Novel Coronavirus ◽  
Public Health Strategies

AbstractIn 2020, the world experienced its very first pandemic of the globalized era. A novel coronavirus, SARS-CoV-2, is the causative agent of severe pneumonia and has rapidly spread through many nations, crashing health systems and leading a large number of people to death. In Brazil, the emergence of local epidemics in major metropolitan areas has always been a concern. In a vast and heterogeneous country, with regional disparities and climate diversity, several factors can modulate the dynamics of COVID-19. What should be the scenario for inner Brazil, and what can we do to control infection transmission in each of these locations? Here, a mathematical model is proposed to simulate disease transmission among individuals in several scenarios, differing by abiotic factors, social-economic factors, and effectiveness of mitigation strategies. The disease control relies on keeping all individuals’ social distancing and detecting, followed by isolating, infected ones. The model reinforces social distancing as the most efficient method to control disease transmission. Moreover, it also shows that improving the detection and isolation of infected individuals can loosen this mitigation strategy. Finally, the effectiveness of control may be different across the country, and understanding it can help set up public health strategies.

scholarly journals Ligusticum sinense Nanoemulsion Gel as Potential Repellent against Aedes aegypti, Anopheles minimus, and Culex quinquefasciatus (Diptera: Culicidae)

Insects ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 596
Author(s):  
Anuluck Junkum ◽  
Wanchai Maleewong ◽  
Atiporn Saeung ◽  
Danita Champakaew ◽  
Arpaporn Chansang ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Disease Transmission ◽  
Skin Irritation ◽  
Mosquito Vectors ◽  
Plant Family ◽  
Anopheles Minimus ◽  
Human Volunteers ◽  
Nanoemulsion Gel ◽  
Fresh Preparation

Ligusticum sinense Oliv. cv. is a species of Umbelliferae (Apiaceae), a large plant family in the order Apiales. In this study, L. sinense hexane extract nanoemulsion gel (LHE-NEG) was investigated for mosquito repellency and compared to the standard chemical, N,N-diethyl-3-methylbenzamide (DEET), with the goal of developing a natural alternative to synthetic repellents in protecting against mosquito vectors. The results demonstrated that LHE-NEG afforded remarkable repellency against Aedes aegypti, Anopheles minimus, and Culex quinquefasciatus, with median protection times (MPTs) of 5.5 (4.5–6.0), 11.5 (8.5–12.5), and 11.25 (8.5–12.5) h, respectively, which was comparable to those of DEET-nanoemulsion gel (DEET-NEG: 8.5 (7.0–9.0), 12.0 (10.0–12.5), and 12.5 (10.0–13.5) h, respectively). Evaluation of skin irritation in 30 human volunteers revealed no potential irritant from LHE-NEG. The physical and biological stability of LHE-NEG were determined after being kept under heating/cooling cycle conditions. The stored samples of LHE-NEG exhibited some changes in appearance and differing degrees of repellency between those kept for 3 and 6 heating/cooling cycles, thus providing slightly shorter MPTs of 4.25 (4.0–4.5) and 3.25 (2.5–3.5) h, respectively, when compared to those of 5.0 (4.5–6.0) h in fresh preparation. These findings encourage commercially developed LHE-based products as an alternative to conventional synthetic repellents in preventing mosquito bites and helping to interrupt mosquito-borne disease transmission.

scholarly journals Is it possible to estimate the need for surgical management in patients with a tubo-ovarian abscess at admission? A retrospective long-term analysis

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Murat Gözüküçük ◽  
Esra Gülen Yıldız
Keyword(s):  
Surgical Treatment ◽  
Antibiotic Therapy ◽  
Treatment Failure ◽  
Medical Treatment ◽  
Length Of Hospital Stay ◽  
Treatment Modalities ◽  
Laboratory Findings ◽  
Factors Affecting ◽  
Laboratory Infection ◽  
Major Factors

Abstract Background This study aimed to determine the possible prognostic factors correlated with the treatment modalities of tubo-ovarian abscesses (TOAs) and thus to assess whether the need for surgery was predictable at the time of initial admission. Materials and methods Between January 2012 and December 2019, patients who were hospitalized with a TOA in our clinic were retrospectively recruited. The age of the patients, clinical and sonographic presentation, pelvic inflammatory risk factors, antibiotic therapy, applied surgical treatment, laboratory infection parameters, and length of hospital stay were recorded. Results The records of 115 patients hospitalized with a prediagnosis of TOA were reviewed for the current study. After hospitalization, TOA was ruled out in 19 patients, and data regarding 96 patients was included for analysis. Twenty-eight (29.2%) patients underwent surgical treatment due to failed antibiotic therapy. Sixty-eight (70.8%) were successfully treated with parenteral antibiotics. Medical treatment failure and need for surgery were more common in patients with a large abscess (volume, > 40 cm3, or diameter, > 5 cm). The group treated by surgical intervention was statistically older than the patients receiving medical treatment (p < 0.05). Conclusions Although the treatment in TOA may vary according to clinical, sonographic, and laboratory findings; age of patients, the abscess size, and volume were seen as the major factors affecting medical treatment failure. Moreover, TOA treatment should be planned on a more individual basis.

Comparison of the Effect of Insecticides on Bumble Bees (Bombus impatiens) and Mosquitoes (Aedes aegypti and Culex quinquefasciatus) by Standard Mosquito Research Methods

2020 ◽  
Author(s):  
Bethany L McGregor ◽  
Bryan V Giordano ◽  
Alfred E Runkel ◽  
Herbert N Nigg ◽  
H Lee Nigg ◽  
...  
Keyword(s):  
Aedes Aegypti ◽  
Culex Quinquefasciatus ◽  
Mosquito Control ◽  
The United States ◽  
Field Trials ◽  
Bombus Impatiens ◽  
Acute Effects ◽  
Nontarget Effects ◽  
Native North American ◽  
Significant Mortality

Abstract Mosquito control districts in the United States are limited to two main classes of adulticides, pyrethroids and organophosphates, to control mosquitoes. Two adulticides used to control domestic mosquitoes are Fyfanon EW (malathion, organophosphate) and DeltaGard (deltamethrin, pyrethroid). While the effect of these pesticides on European honeybees (Apis mellifera L., Hymenoptera: Apidae) has been investigated, effects on native pollinators need additional research. The purpose of this study was to investigate the acute nontarget effects of these pesticides on Bombus impatiens Cresson (Hymenoptera: Apidae), a native North American bumble bee species, and compare these effects to wild and laboratory strains of mosquitoes (Aedes aegypti (L.) and Culex quinquefasciatus Say, Diptera: Culicidae) through field and laboratory assays. Bombus impatiens was found to be resistant to Fyfanon EW (x̅ = 6.7% mortality at 50-µg malathion per bottle) at levels that caused significant mortality to study mosquitoes (86.2 ≥ x̅ ≥ 100% mortality) in laboratory bottle bioassays. Comparatively, B. impatiens demonstrated greater mortality to DeltaGard (93.3%) at 2.5-µg deltamethrin/bottle than any mosquito colony assayed (14.1 ≥ x̅ ≥ 87.0% mortality). Only DeltaGard was tested in field applications. In the field, we observed acute effects of DeltaGard on mosquitoes and B. impatiens at 25- and 75-m distance from a truck-mounted ultra-low volume fogger, although treatment effects were not significant for B. impatiens. Additional wild-caught nontarget mortality to DeltaGard field trials was also evaluated. This study indicated that common mosquito control adulticides do cause nontarget mortality to B. impatiens but that impacts are variable depending on pesticide and further studies are needed.

Review of the impact Covid-19 has on the Psychosocial factors affecting Well-Being

2021 ◽  
pp. 3404-3408
Author(s):  
Sheila Menon FBSCH ◽  
Vidya Bhagat
Keyword(s):  
Psychosocial Factors ◽  
Health Workers ◽  
Public Awareness ◽  
Cost Effective ◽  
Well Being ◽  
Security Measures ◽  
Post Traumatic Stress ◽  
Negative Effects ◽  
Factors Affecting ◽  
The Impact

The COVID-19 pandemic has had a significant impact on the psychosocial factors that effect people globally. Particularly affected are children, students and health workers and the common symptoms identified are stress, anxiety disorders, depression and post-traumatic stress disorder. In addition, the various security measures implemented to ensure public safety have adversely affected relationships between people. This study directs public awareness to the value of psychotherapeutic support. Tele-therapy can be offered easily to people both at home or in the workplace, providing both cost effective and time sensitive solutions during times of crisis. The current review article provides an overview of the importance of maintaining psychological well-being during a pandemic and the identifies the role that empathetic communication has on wellbeing. The literature review was completed using electronic databases such as PubMed, Medline, and Scopus databases using the keywords covid-19, affected groups, affected relationships, psychology and its technological interventions, negative effects of pandemic so on.

scholarly journals Study on the Factors Affecting the Financing of High-Tech SMEs

2017 ◽  
Vol 13 (8) ◽  
pp. 121
Author(s):  
Mingjun Zhu
Keyword(s):  
Positive Relationship ◽  
Significance Test ◽  
High Tech ◽  
Negative Effects ◽  
Factors Affecting ◽  
Enterprise Growth ◽  
Tax Shield ◽  
Debt Tax Shield ◽  
Major Factors ◽  
Tangible Asset

High-tech small and medium-sized enterprises (SMEs) have played an important role in promoting the development of Chinese national economy, but most of them are still facing the difficulty in financing. This paper determines the major factors affecting the financing for high-tech SMEs by using multiple linear regression (MLR) method and significance test then comes to a conclusion that enterprise scale, enterprise growth, tangible asset ratio and equity liquidity have positive relationship with the financing of high-tech SMEs while profitability, accumulation, non-debt tax shield and solvency have negative effects.

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