scholarly journals Impact of climate and hydrochemistry on shape variation – a case study on Neotropical cytheroidean Ostracoda

2017 ◽  
Author(s):  
Claudia Wrozyna ◽  
Thomas A. Neubauer ◽  
Juliane Meyer ◽  
Maria Ines F. Ramos ◽  
Werner E. Piller
Keyword(s):  
Least Squares ◽  
Shape Change ◽  
Morphological Variability ◽  
Morphological Characteristics ◽  
Generalized Least Squares ◽  
Structural Features ◽  
Shape Variation ◽  
Valve Morphology ◽  
Temperature Seasonality ◽  
The Impact

Abstract. How environmental change affects a species’ phenotype is crucial not only for taxonomy and biodiversity assessments but also for their application as (paleo-)ecological indicators. Previous investigations addressing the impact of climate and hydrochemical regime on ostracod valve morphology have yielded quite contrasting results. Frequently identified ecological factors influencing carapace shape are salinity, cation and sulphate concentrations and alkalinity. Here, we present a thorough approach integrating data from carapace outline and surface details of the ubiquitous Neotropical cytheroidean ostracod species Cytheridella ilosvayi, as well as several climatic and hydrochemical variables, in order to investigate a potential link between morphology and environmental conditions. A previous study lately demonstrated considerable biogeographical variation in valve morphology among Floridian, Mexican and Brazilian populations of this species. We hypothesize that the climatic differences between the regions it inhabits and associated differences in hydrochemical regimes have influenced valve morphology and eventually led to biogeographically distinctive groups. Generalized least-squares Procrustes Analyses based on outline and structural features were applied to left and right valves of adult females and males. The analyses identified relative carapace length and shape symmetry as most important morphological characteristics representing shape change across all datasets. Two-block partial least-squares analyses and multiple regressions indicate strong relationships between morphological and environmental variables, specifically with temperature seasonality, annual precipitation and chloride and sulphate concentrations. We hypothesize that increased temperature seasonality slowed down growth rates during colder months, potentially triggering the development of shortened valves with well-developed brood pouches. Differences in chloride and sulphate concentrations, related to fluctuations in precipitation, are considered to affect valve development via controlling osmoregulation and carapace calcification. These factors represent hitherto unknown drivers for ostracod ecophenotypy and emphasise that environmental predictors for morphological variability are not consistent across non-marine ostracods.

scholarly journals Significance of climate and hydrochemistry on shape variation – a case study on Neotropical cytheroidean Ostracoda

2018 ◽  
Vol 15 (17) ◽  
pp. 5489-5502 ◽  
Author(s):  
Claudia Wrozyna ◽  
Thomas A. Neubauer ◽  
Juliane Meyer ◽  
Maria Ines F. Ramos ◽  
Werner E. Piller
Keyword(s):  
Least Squares ◽  
Morphological Variability ◽  
Morphological Characteristics ◽  
Generalized Least Squares ◽  
Structural Features ◽  
Ecological Indicator ◽  
Shape Variation ◽  
Valve Morphology ◽  
Temperature Seasonality ◽  
The Impact

Abstract. How environmental change affects a species' phenotype is crucial not only for taxonomy and biodiversity assessments but also for its application as a palaeo-ecological and ecological indicator. Previous investigations addressing the impact of the climate and hydrochemical regime on ostracod valve morphology have yielded contrasting results. Frequently identified ecological factors influencing carapace shape are salinity, cation, sulfate concentrations, and alkalinity. Here, we present a thorough approach integrating data with the carapace outline and surface details of the ubiquitous Neotropical cytheroidean ostracod species Cytheridella ilosvayi, as well as several climatic and hydrochemical variables, in order to investigate a potential link between morphology and environmental conditions. A recent study previously demonstrated considerable biogeographical variation in valve morphology among Floridian, Mexican and Brazilian populations of this species. We hypothesize that the climatic differences between the regions it inhabits and associated differences in hydrochemical regimes have influenced valve morphology and eventually led to biogeographically distinctive groups. Generalized least-squares Procrustes analyses based on outline and structural features were applied to the left and right valves of adult females and males. The analyses identified relative carapace length and shape symmetry as most important morphological characteristics representing shape differences across all datasets. Two-block partial least-squares analyses and multiple regressions indicate strong relationships between morphological and environmental variables, specifically with temperature seasonality, annual precipitation and chloride and sulfate concentrations. We suggest that increased temperature seasonality slowed down growth rates during colder months, potentially triggering the development of shortened valves with well-developed brood pouches. Differences in chloride and sulfate concentrations, related to fluctuations in precipitation, are considered to affect valve development via controlling osmoregulation and carapace calcification. The factors identified by our analyses represent hitherto unknown drivers for ostracod ecophenotypy in other species and therefore suggest that environmental predictors for morphological variability are not consistent across non-marine ostracods.

How Credit Portfolio Diversification Affects the Profitability of Vietnamese Commercial Banks

2020 ◽  
pp. 237-255
Author(s):  
Huynh Viet Khai ◽  
Phan Thi Anh Nguyet ◽  
Phan Dinh Khoi ◽  
Chu Van Nam
Keyword(s):  
Least Squares ◽  
Commercial Banks ◽  
Inflation Rate ◽  
Generalized Least Squares ◽  
Portfolio Diversification ◽  
Credit Growth ◽  
Positive Correlation ◽  
Credit Portfolio ◽  
The Impact

This study analyzed the impact of credit portfolio diversification on the profitability by using the data of 20 Vietnam commercial banks from 2009 to 2015. The results from feasible generalized least squares (FGLS) estimation show that the strategy of diversifying the credit portfolio increased the profitability of commercial banks. In addition, the study also indicates that the positive correlation of the ratio of owners' equity, credit growth, liquidity, assets, inflation rate with the profitability while the increase in non-performing loan decreased the profitability of these commercial banks.

scholarly journals Extreme return, extreme volatility and investor sentiment

Filomat ◽  
2016 ◽  
Vol 30 (15) ◽  
pp. 3949-3961 ◽  
Author(s):  
Xu Gong ◽  
Fenghua Wen ◽  
Zhifang He ◽  
Jia Yang ◽  
Xiaoguang Yang ◽  
...  
Keyword(s):  
Linear Regression ◽  
Quantile Regression ◽  
Regression Model ◽  
Least Squares ◽  
Linear Regression Model ◽  
Investor Sentiment ◽  
Generalized Least Squares ◽  
Regression Methods ◽  
Leading Role ◽  
The Impact

The extreme return and extreme volatility have great influences on the investor sentiment in stock market. However, few researchers have taken the phenomenon into consideration. In this paper, we first distinguish the extreme situations from non-extreme situations. Then we use the ordinary generalized least squares and quantile regression methods to estimate a linear regression model by applying the standardized AAII, the return and volatility of SP 500. The results indicate that, except for extremely negative return, other return sequences can cause great changes in investor sentiment, and non-extreme return plays a leading role in affecting the overall American investor sentiment. Extremely positive (negative) return can rapidly improve (further reduce) the level of investor sentiment when investors encounter extremely pessimistic situations. The impact gradually decreases with improvement of the sentiment until the situation turns optimistic. In addition, we find that extreme and non-extreme volatility cannot a_ect the overall investor sentiment.

The determinants of the hotel sector revenues: The case of French Polynesia

2019 ◽  
Vol 26 (5) ◽  
pp. 809-829
Author(s):  
Gil Montant
Keyword(s):  
Least Squares ◽  
Generalized Least Squares ◽  
French Polynesia ◽  
Ordinary Least Squares ◽  
Panel Regression ◽  
Geographical Distance ◽  
Explanatory Variables ◽  
Basic Model ◽  
Hotel Sector ◽  
The Impact

This article is an empirical analysis focused on the hotel sector in French Polynesia in 2007–2017. One assesses the impact of a set of variables on the French Polynesian hotel sector monthly revenues through a gravity model. First, one specifies a basic model that embeds several potential explanatory variables (the exchange rate (both nominal and real), the rate of unemployment, the geographical distance, some specific historical events, etc.). Next, a second model is specified so as to assess the impact of hotel capacities measured by the number of bedrooms offered. Estimates rest on an unbalanced monthly panel database that embeds main countries from where tourists present in French Polynesia are originated. In order to compare results, each specification is estimated by two methods: classical panel regression (Ordinary least squares /Generalized least squares) and pseudo Poisson maximum likelihood. Both methods lead to coherent results.

Morphological variation of Jovibarba heuffelii (Crassulaceae) in the central Balkan Peninsula—The impact of geological, orographical and bioclimatic factors on the differentiation of populations

Phytotaxa ◽  
2015 ◽  
Vol 203 (3) ◽  
pp. 213
Author(s):  
Danijela Nikolić ◽  
Jasmina Šinžar-Sekulić ◽  
Vladimir Ranđelović ◽  
Dmitar Lakušić
Keyword(s):  
Morphological Variation ◽  
Morphological Variability ◽  
Morphological Characteristics ◽  
Balkan Peninsula ◽  
Secondary Importance ◽  
Mahalanobis Distances ◽  
Geographical Position ◽  
Bioclimatic Conditions ◽  
The Impact ◽  
Spearman’S Correlation

The aim of this study was to quantify and compare morphological variation between 14 populations of J. heuffelii distributed in Serbia, Romania, Bulgaria and Macedonia and to correlate their morphological characteristics with the geomorphologic and bioclimatic parameters of their habitats. For these purposes, several multivariate analyses (PCA, CDA, clustering UPGMA analysis based on Mahalanobis distances, MCA, and Spearman’s correlation) of the vegetative and generative plant organs were performed. Analyses showed that apart from the overall morphological variability, which is related to environmental conditions, there are four groups of populations that are morphologically distinct. Although the results clearly indicate the significant influence of environmental factors (elevation, aspect and slope) on the morphology of the species, we found that recent bioclimatic conditions, geological substratum and geographical position are only of secondary importance in the pattern of morphological variation in J. heuffelii in the area investigated.

Liberalization, Import of Capital Goods, and Industrial Exports: Evidence from Indian Manufacturing Sectors

2020 ◽  
pp. 239395752097478
Author(s):  
R. Rijesh
Keyword(s):  
Least Squares ◽  
Positive Impact ◽  
Manufacturing Sector ◽  
Generalized Least Squares ◽  
Ordinary Least Squares ◽  
Capital Goods ◽  
Export Prices ◽  
Manufacturing Sectors ◽  
World Demand ◽  
The Impact

This article examines the impact of capital goods import on Indian manufacturing exports at the sectoral level. Import of capital goods provides dynamic productivity gains through quality, variety, and cost-efficiency channels that further boost manufacturing exports. Since trade liberalization facilitates this process, we presumed that better access to capital inputs would enhance Indian exports for 15 major manufacturing sectors at the 3-digit level from 1997 to 2016. The panel regression analysis based on fixed effect(s) feasible generalized least squares (FGLS), and ordinary least squares (OLS) indicate that, after controlling for world demand, relative export prices, and in-house research and development (R&D), the capital goods import has a positive and statistically significant impact on the aggregate manufacturing sector. The OLS estimates at the sectoral level further confirm the positive impact across nine major sectors. In general, the engineering sectors such as metals, machinery and transport equipment, and traditional labor-intensive sectors like textiles show positive benefit from these technology imports.

scholarly journals The Impact of Trade Credit Investment on Manufacturing Firms' Profitability: Evidence from Vietnam

2020 ◽  
Vol 68 (4) ◽  
pp. 775-796
Author(s):  
Duong Phuong Thao Pham ◽  
Thi Cam Ha Huynh
Keyword(s):  
Firm Performance ◽  
Panel Data ◽  
Least Squares ◽  
Random Effects ◽  
Fixed Effects ◽  
Trade Credit ◽  
Generalized Least Squares ◽  
Manufacturing Firms ◽  
Return On Assets ◽  
The Impact

The aim of this study is to examine the effect that trade credit investment has on firms' profitability. The characteristics of this relationship have not been dealt with in depth for manufacturing firms. We use panel data for a total of 227 Vietnamese publicly listed manufacturing firms for the period 2005–2017. Different econometric estimation techniques such as the feasible generalized least squares, fixed effects and random effects and different calculation of firm performance such as non market-based measure (return on assets) and market-based measure (Tobin's q) are employed to validate the consistent results. The robust results confirm a statistically significant inverted U-shaped relationship between trade credit investment and profitability.

scholarly journals Timely loss recognition in Brazilian firms under corruption investigation

2021 ◽  
Vol 32 (86) ◽  
pp. 224-240
Author(s):  
Silvia Pereira da Rocha ◽  
Francisco Antonio Bezerra
Keyword(s):  
Least Squares ◽  
Accounting Information ◽  
Estimation Method ◽  
Generalized Least Squares ◽  
Ordinary Least Squares ◽  
Business Environment ◽  
Quality Of Accounting Information ◽  
Accounting Reports ◽  
The Impact

ABSTRACT This article evaluates the impact of the disclosure of the participation of Brazilian firms listed on the Bolsa Brasil Balcão (B3) in corruption scandals through media scrutiny and by disclosure of independent auditors on the quality of accounting information, measured from the perspective of accounting conservatism. We examine the possible theoretical link between the disclosure of corruption scandals and the quality of accounting information in the Brazilian context. Brazil has gone through successive corruption scandals involving firms and government entities in different levels. Accounting can be an important tool to mitigate said risks based on the artifacts it has to inform key stakeholders. However, it is necessary to identify the extent to which these artifacts can be influenced by the actors involved in these scandals. The research places accounting as an instrument subject to pressures from different interests and that may be shaped to them. Although accounting is an instrument that must aim to reduce information asymmetry, preventing the harmful effects of corruption, in specific contexts, it can be used in the opposite direction, such as in cases of corruption and economic crises. We used the model based on Ball and Shivakumar (2005) with specific modeling characteristics for corruption and crisis. The models were estimated using the Stata 13 software using the pooled approach using the Ordinary Least Squares (OLS) estimation method, clustered by year and economic sector, and the Generalized Least Squares (GSL) estimator. The results point to the presence of conservatism when disclosing involvement in investigations of corruption crimes in Brazil. This behavior was less intense in firms effectively mentioned in these events. These results highlight the relevance of studies aimed at clarifying the connections between corruption and accounting reports, enabling the development of measures to curb corruption in the business environment.

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