scholarly journals Masculinization of Tropical Eel Anguilla bicolor McClelland in Different Population Density

2020 ◽  
Vol 25 (3) ◽  
pp. 97-102
Author(s):  
Farida Nur Rachmawati ◽  
Yulia Sistina

In general, female eel dominates the results of catching eel in the river. Male fish dare rarely found in nature, therefore masculinization is necessary for obtaining in males.  The administration of 17α-methyltestosterone  to masculinize Anguilla bicolor McClelland.   It is a synthetic anabolic-androgenic steroid which has potential to endocrine disrupter that disturbed function of normal reproduction in human or animal. It urgently needed that a masculinization technique needs to study the use of an environmental factor. Population density is one of the environmental factors that influence gender determination (ESD-environmental dependent sex determination). This will result in increased cortisol secretion, which will further stimulate the synthesis of 11-KT steroids that affect male gonad differentiation. This study aims to induce masculinization in tropical eel Anguilla bicolor McClelland in different density. Three treatments and three replicates conducted the research. The treatments were one fish.48 L-1, two fish.48 L-1   and three fish.48 L-1.  Eels size was approximately similar, at 16,78 g±0,62 in weight, and 25,38 cm±0,15 in length were either culture in brackish water for eight weeks. The results showed that density population treatment significantly increased the Fin Index (P<0.05), but no sign for Eye Index, GSI, HSI, and testosterone level. The highest male population (77,8%) achieves at the highest density treatment, three fish.48 L-1 population density. It can be concluded, based on reproductive observations, population density does not affect gonad maturity/puberty, but the high population density (3 fish.48 L-1)stimulates Anguilla bicolor McClelland masculinization.

2020 ◽  
Vol 26 (105) ◽  
pp. 131-154
Author(s):  
Luis Eduardo Sandoval-Garrido ◽  

In some countries, the increase in the youth population is connected to greater criminal activity. In the case of Colombia, different studies support the idea of providing socio-economic possi-bilities for young people to avoid being linked to illegal and criminal activities. Based on these precedents, this document examines whether the increase in the youth population in Colombia is directly connected to municipal crime during 2000-2010, a period in which those born in the 1990’s reached their teenage years and could participate in urban crime. For this study, economic and other variables of total and juvenile population are constructed for youth between the ages of 15-24, as well as variables in population density and political polarization incorporating the crime index proposed by (Durán, López, & Restrepo, 2009). The proposed model estimates that youth population density, population growth, conflict actions and political polarization are asso-ciated with an increase in crime. Also, greater development and political polarization can lead to an environment of less crime.


1986 ◽  
Vol 64 (9) ◽  
pp. 1820-1826 ◽  
Author(s):  
Rupert C. P. Lee ◽  
Patrick McGinn

Observations of territorial behaviour of male Nannothemis bella indicated that females only laid eggs on males' territories after copulating with the territory holder. Results of daily censuses of marked individuals on a study area suggested that a distinct subpopulation within the male population never retained a territory for more than 1 day on the study area. Such males tend to die or emigrate sooner than do males that hold a territory on the study area for more than 1 day at some time in their lives. Further observations of territorial behaviour showed that males holding territories for less than 1 day achieved copulations at significantly lower overall rates while on those territories than did males that retained territories for more than 1 day. We infer that all males attempt to hold territories for as long as possible, but under conditions of high population density a male must have a relatively high intrinsic "territory-holding ability" in order to hold a territory for more than 1 day. Census data indicated that males emerging late in the season were less likely to retain a territory for more than 1 day than males emerging earlier.


2021 ◽  
Vol 5 (2) ◽  
pp. 126
Author(s):  
Weka Weka ◽  
Sawaludin Sawaludin ◽  
Anita Indriasary ◽  
Weko Indira Romanti Aulia ◽  
Saban Rahim

Abstrak: Isu pandemi Covid-19 menjadi perhatian dunia dan sampai saat ini belum diprediksi kapan akan berakhir. Penyebaran Covid-19 merubah pola interaksi dalam kurun waktu yang cepat dan drastis karena adanya pemberlakukan pembatasan pergerakan dan kegiatan manusia. Kota Kendari termasuk daerah yang terdampak penyebaran Covid-19 dan salah satu kelurahan yang terdampak dengan status zona merah adalah kelurahan Kadia. Dalam mengantisipasi penyebaran Covid-19 di kelurahan Kadia, perlu dilakukan mitigasi melalui pemetaan kepadatan pemukiman, mobilitas penduduk dan lingkungan. Tujuan kegiatan ini adalah melakukan mitigasi penyebaran Covid-19 melalui pemetaan kepadatan pemukiman, mobilitas penduduk dan lingkungan kelurahan Kadia. Metode yang digunakan dalam penelitian ini adalah survey dan overlay peta. Hasil penelitian menunjukan kepadatan pemukiman di kelurahan Kadia pada tingkat yang tinggi (25-34) pada RW 002, RW 007 dan RW 008. Kepadatan penduduk di kelurahan Kadia yang tinggi pada (62-92) pada RW 001 RT 002, RW 002, RW 007 RT 001 dan 003, RW 008 RT 003, dan RW 009 RT 003. Tingkat mobilitas penduduk dikelurahan Kadia yang tinggi (90-174) pada RW 002 RT 002, RW 003 RT 001 dan 002, RW 004 RT001, 002 dan 003, RW 005 RT 001, RW 006 RT 001, dan RW 007. Secara spasial kondisi lingkungan kelurahan Kadia didominasi oleh lahan terbangun dengan jumlah penduduk sebanyak 7775 jiwa. Berdasarkan hasil pemetaan kepadatan pemukiman, kepadatan penduduk, mobilitas penduduk dan lingkungan maka mitigasi tingkat potensial penyebaran Covid-19 di kelurahan Kadia difokuskan pada titik potensial yang tinggi (RW 002) dan titik potensial yang sedang (RW 007). Beberapa langkah mitgasi penyebaran Covid-19 yang dilakukan adalah memasang poster mitigasi penerapan protokol kesehatan dengan memakai masker, selalu mencuci tangan dengan sabun dan menjaga jarak.Kata kunci : Mitigasi, Pandemi Covid-19, Pemetaan, Kelurahan Kadia Abstract: The issue of the Covid-19 pandemic has become a worldwide concern and until now it has not been predicted when it will end. The spread of Covid-19 changed the pattern of interaction in a fast and drastic period due to the imposition of restrictions on human movement and activities. Kendari City is one of the areas affected by the spread of Covid-19 and one of the ward affected by the red zone status is Kadia Ward. In anticipating the spread of Covid-19 in the Kadia sub-district, it is necessary to carry out mitigation through mapping the density of settlements, population mobility, and the environment. The purpose of this activity is to mitigate the spread of Covid-19 through mapping the density of settlements, population mobility, and the Kadia urban village environment. The method used in this research is survey and map overlay. The results showed that the density of settlements in the Kadia village was at a high level (25-34) in RW 002, RW 007, and RW 008. The population density in the Kadia ward was high at (62-92) in RW 001, RT 002, RW 002, RW. 007 RT 001 and 003, RW 008 RT 003, and RW 009 RT 003. The level of population mobility in Kadia kelurahan is high (90-174) in RW 002 RT 002, RW 003 RT 001 and 002, RW 004 RT 001, 002 and 003, RW 005,RT 001, RW 006, RT 001, and RW 007. Spatially, the environmental condition of the Kadia ward is dominated by built-up land with a population of 7775 people. Based on the results of mapping settlement density, population density, population mobility, and the environment, mitigation of the potential level of Covid-19 spread in the Kadia ward is focused on high potential points (RW 002) and medium potential points (RW 007). Some of the steps to mitigate the spread of Covid-19 were putting up a mitigation poster for the implementation of the health protocol by wearing a mask, always washing hands with soap, and keeping a distance.Keywords : Mitigation, Covid-19 Pandemic, Mapping, Kelurahan Kadia


Biospecies ◽  
2017 ◽  
Vol 10 (1) ◽  
Author(s):  
Hendrival HENDRIVAL ◽  
Lilis MELINDA

The research aims to study the effect population density of S. oryzae against population growth and damage of rice. The population density of S. oryzae is 5, 10, 15, and 20 pairs of adult per 250 g rice. The results showed that population density S. oryzae affects pest population growth of S. oryzae, characteristics loses weight of rice, percentage powder of rice, and changes content moisture of rice. The population density S. oryzae as many as 20 pairs of adult per 250 g of rice can increase populations pest S. oryzae, characteristics loses weight of rice, percentage powder of rice, and content moisture of rice. The relationship between population density S. oryzae with a growing population, percentage loses weight, percentage rice hollow, percentage powder of rice, and changes content moisture of rice increased linearly. There is a positive correlation between population density S. oryzae with population growth S. oryzae (r = 0.997**; P < 0.01), the percentage loses weight (r = 0.987*; P < 0.05), the percentage of rice perforated (r = 0.998**; P < 0.01), the percentage powder of rice (r = 0.997**; P < 0.01), and changes content moisture of rice (r = 0.964**; P < 0.01)Keywords: Sitophilus oryzae, population density, population growth, damage rice


2020 ◽  
Author(s):  
Andrew Rideout ◽  
Calum Murray ◽  
Chris Isles

AbstractBackgroundCovid-19 virus activity appears to have affected some parts of the United Kingdom more than others. Dumfries and Galloway (D&G) has seen fewer hospitalised cases than predicted. We wondered whether this might be related at least in part to population density.MethodsWe compared Covid-19 hospitalisation rates/100,000 population in D&G with those of the other 10 mainland Scottish health boards. We chose two time points: 19th April which was the peak of the pandemic in Scotland and 15th May, seven and a half weeks after lockdown. We used chi square and odds ratios with 95% confidence intervals to test for differences in hospitalisation rates and Pearson’s correlation coefficient to examine the relation between hospitalisation rates and population density. Population density for each health board was provided by National Records of Scotland.ResultsHospitalisation in D&G was 13.4/100,000 on 19th April, falling to 1.3/100,000 by 15th May. Corresponding hospitalisation rates in Greater Glasgow & Clyde (GGC) were 50.1/100,000 and 38.9/100,000. Compared to GGC, hospitalisation rates in D&G were 3 times lower at peak (OR 0.27, 95% CI 0.17, 0.42) and 30 times lower by 15th May (OR 0.03, 95% CI 0.01, 0.14). Hospitalisation rates for the other health boards lay in between values recorded for D&G and GGC and fell in 10 of the 11 boards between these two dates. There was a positive association between hospitalisation rate and population density (r=0.756, p=0.007 on 19th April and r=0.840, p<0.001 for 15th May).ConclusionWe have confirmed there are large differences in Covid-19 hospitalisation rates across the 11 mainland Scottish health boards, that are in part related to population density. These data support a regional rather than one nation approach to easing Covid-19 restrictions.


1992 ◽  
Vol 72 (3) ◽  
pp. 901-909 ◽  
Author(s):  
M. M. Gaye ◽  
P. A. Jolliffe ◽  
A. R. Maurer

Row cover and plant population density effects were studied at the Agriculture Canada Research Station, Agassiz, BC in 1988 and 1989. Bell pepper plants (Ace Hybrid) were transplanted into twin rows (0.45 m apart) on raised beds (1.8-m centers) at five population densities of 1.39, 1.85, 2.78, 5.56 and 11.1 plant m−2. For 7 wk in 1988 or 8 wk in 1989, subplots were either covered or not covered with slit clear polyethylene tunnels. A nonlinear regression model was used to define yield-population density responses. Row covers enhanced early and overall yields in 1988 and overall yield in 1989. Vegetative and reproductive yields (kg plant−1) declined with increasing plant population density. Yields were directly related to population density when measured on a land-area basis. Maximum fruit yield (7.9 kg m−2) was obtained at the highest population density. Treatment influences on fruit size were small and did not affect horticultural quality. An economic analysis showed that net returns were greatest with plants grown under row covers at the highest population density.Key words: Capsicum annuum L., field bell peppers, population density, row covers


2014 ◽  
Vol 6 (4) ◽  
pp. 434-444 ◽  
Author(s):  
G. B. Raga ◽  
M. G. de la Parra ◽  
Beata Kucienska

Abstract This paper presents evidence of the geographical distribution of deaths due to lightning over Mexico for the period 1979–2011. Over 7300 deaths occurred during this period, an average of 230 per year, which translates into an average fatality rate per million inhabitants of 2.72 (1979–2011). A total of 60% of the fatal victims occur in only 7 out of the 32 states in Mexico, with the largest fraction occurring in the state of Estado de México (24%). The largest death toll is found in the young male population, in rural regions of the states of Estado de México, Michoacán, and Oaxaca, where the population density is low. The results have indicated a clear bias in the fatal victims toward boys and young males (under the age of 25), with more than 45% of the total deaths in that segment of the population. While female deaths constitute a small fraction of the total number, the under-25 age segment also has the largest number of fatal victims. A county-level analysis of socioeconomic indicators clearly suggests that the geographical distribution of deaths is not correlated with population density nor with the maximum lightning density, but rather with vulnerability. The spatial distribution of deaths is better correlated with exposure to thunderstorms, agricultural activities, and low education levels. The large social vulnerability of those regions combined with the lack of recognition of the problem by society and the government are more likely responsible for the large death toll.


2015 ◽  
Vol 20 (2) ◽  
pp. 113-115
Author(s):  
Maria Grozeva ◽  
Radoswet Gornev ◽  
Vania Mitova ◽  
Rossen Hadjiev ◽  
Miroslav Zashev ◽  
...  

Gynecomastia is a benign enlargement of the male breast, secondary to gland proliferation and is a common problem among the male population. Treatment is primarily surgical. The most common intra- and postoperative complication is bleeding, followed by seroma, infection, insufficient results, inverted nipple and nipple necrosis. The embolism is one of the non-specific complications. A 24-year-old male was presented to the Surgery Department with a diagnosis unilateral gynecomastia. The operation proceeded without complication and around 10 hours later, the patient complained of weakness in all four limbs, later nausea, and vomiting and after full cardiopulmonary resuscitation, the patient died. The main reason for the patient’s death was concluded to be a postoperative pulmonary thromboembolism and fat embolism was discovered. In addition, there was a papillary carcinoma of the thyroid, which was missed before. We reported that unilateral gynecomastia associated with papillary carcinoma of the thyroid detected rarely at autopsy and fat embolism after surgery for gynecomastia is a rare complication.Key words: Gynecomastia, fat embolism, autopsy


2020 ◽  
Vol 376 (1816) ◽  
pp. 20190716 ◽  
Author(s):  
W. Archer

As is the case today, both climate variability and population density influenced human behavioural change in the past. The mechanisms underpinning later Pleistocene human behavioural evolution, however, remain contested. Many complex behaviours evolved in Africa, but early evidence for these behaviours varies both spatially and temporally. Scientists have not been able to explain this flickering pattern, which is present even in sites and regions clearly occupied by Homo sapiens . To explore this pattern, here the presence and frequency of evidence for backed stone artefact production are modelled against climate-driven, time-series population density estimates (Timmermann and Friedrich. 2016 Nature 538 , 92. ( doi:10.1038/nature19365 )), in all known African Late Pleistocene archaeological sites ( n = 116 sites, n = 409 assemblages, n = 893 dates). In addition, a moving-window, site density population estimate is included at the scale of southern Africa. Backed stone artefacts are argued in many archaeological contexts to have functioned in elaborate technologies like composite weapons and, in the African Pleistocene, are accepted proxies for cultural complexity. They show a broad but sporadic distribution in Africa, prior to their association with Homo sapiens dispersing into Europe 45–40 ka. Two independent population estimates explain this pattern and potentially implicate the interaction of climate change and demography in the expression of cultural complexity in African Pleistocene Homo sapiens . This article is part of the theme issue ‘Cross-disciplinary approaches to prehistoric demography’.


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