Evidence of climate-driven regime shifts in the Aegean Sea’s demersal resources: a study spanning six decades

Climate change (CC) can alter the configuration of marine ecosystems, however ecosystem response and resilience to change are usually case-specific. The effect of CC on the demersal resources of the Aegean Sea (east Mediterranean Sea) was investigated during the past six decades applying a combination of multivariate analysis, non-additive modelling and the Integrated Resilience Assessment (IRA) framework. We focused on the study of: (i) the biological ‘system’ complex, using proxies of biomass (landings per unit of capacity) for 12 demersal taxa and (ii) the environmental ‘stressor’ complex, described by 12 abiotic variables. Pronounced changes have occurred in both the environmental and biological system over the studied period. The majority of the environmental stressors exhibited strikingly increasing trends (temperature, salinity, primary production indices) with values started exceeding the global historical means during late 1980s-early 1990s. It is suggested that the biological system exhibited a discontinuous response to CC, with two apparently climate-induced regime shifts occurring in the past 25 years. There is evidence for two fold bifurcations and four tipping points in the system, forming a folded stability landscape with three basins of attraction. The shape of the stability landscape for the Aegean Sea’s biological system suggests that while the initial state (1966-1991) was rather resilient to CC, absorbing two environmental step-changes, this was not the case for the two subsequent ones (intermediate: 1992-2002; recent: 2003-2016). Given the current trajectory of environmental change, it is highly unlikely that the biological system will ever return to its pre-1990s state, as it is entering areas of unprecedented climatic conditions and there is some evidence that the system may be even shifting towards a new state. Our approach and findings may be relevant to other marine areas of the Mediterranean and beyond, undergoing climate-driven regime shifts, and can assist to their adaptive management.

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Effect of Delay on the Boundary of the Basin of Attraction in a Self-Excited Single Graded-Response Neuron

Neural Computation ◽

10.1162/neco.1997.9.2.319 ◽

1997 ◽

Vol 9 (2) ◽

pp. 319-336 ◽

Cited By ~ 18

Author(s):

K. Pakdaman ◽

C. P. Malta ◽

C. Grotta-Ragazzo ◽

J.-F. Vibert

Keyword(s):

Stable Equilibrium ◽

Equilibrium Points ◽

Basin Of Attraction ◽

Basins Of Attraction ◽

Transmission Delays ◽

The Past ◽

Graded Response ◽

The Stability ◽

Delay Dependent ◽

The Basin Of Attraction

Little attention has been paid in the past to the effects of interunit transmission delays (representing a xonal and synaptic delays) ontheboundary of the basin of attraction of stable equilibrium points in neural networks. As a first step toward a better understanding of the influence of delay, we study the dynamics of a single graded-response neuron with a delayed excitatory self-connection. The behavior of this system is representative of that of a family of networks composed of graded-response neurons in which most trajectories converge to stable equilibrium points for any delay value. It is shown that changing the delay modifies the “location” of the boundary of the basin of attraction of the stable equilibrium points without affecting the stability of the equilibria. The dynamics of trajectories on the boundary are also delay dependent and influence the transient regime of trajectories within the adjacent basins. Our results suggest that when dealing with networks with delay, it is important to study not only the effect of the delay on the asymptotic convergence of the system but also on the boundary of the basins of attraction of the equilibria.

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Instability of production of agricultural products: Assessment and analysis features

Zbornik Matice srpske za drustvene nauke ◽

10.2298/zmsdn1868805p ◽

2018 ◽

pp. 803-819

Author(s):

Dmitri Parmacli ◽

Alina Ianioglo

Keyword(s):

Agricultural Production ◽

Moving Average ◽

Safety Margin ◽

Climatic Conditions ◽

Risk Zone ◽

The Past ◽

Land Use Efficiency ◽

Use Efficiency ◽

The Republic ◽

The Stability

The article highlights the presence of unfavourable climatic conditions in the agricultural production of the Republic of Moldova, which adversely affect the results of crop cultivation and the economic sustainability of enterprises. As a rule, the variation indicators are not taken into account and evaluated when calculating the efficiency of crops production and sales, and accordingly, the potential values of land use efficiency in the industry are not correctly predicted. In this regard, the aim of the study is to develop methodo?logical approaches to assess the stability of production and to justify some fea?tures of calculating potential indicators of production and sales of crops. The article shows the dynamics of yield of leading crops over the past 16 years and estimates the instability of production. For this purpose formulas are proposed, with the help of which the level of sustainability of enterprises can be predicted. The suggested interrelationships are vividly presented on graphs. The proposed approaches will allow specialists of enterprises to calculate the financial safety margin and the risk zone for each crop, to predict economic development using, above all, the moving average indicators.

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The evolutionary heritage and ecological uniqueness of Scots pine in the Caucasus ecoregion is at risk of climate changes

Scientific Reports ◽

10.1038/s41598-021-02098-1 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

M. Dering ◽

M. Baranowska ◽

B. Beridze ◽

I. J. Chybicki ◽

I. Danelia ◽

...

Keyword(s):

Scots Pine ◽

Hot Spot ◽

Climatic Conditions ◽

Adaptive Potential ◽

Evolutionary Trajectory ◽

The Caucasus ◽

The Past ◽

Postglacial History ◽

Ecological Uniqueness ◽

The Stability

AbstractScots pine is one of the most widely occurring pines, but future projections suggest a large reduction in its range, mostly at the southern European limits. A significant part of its range is located in the Caucasus, a global hot-spot of diversity. Pine forests are an important reservoir of biodiversity and endemism in this region. We explored demographic and biogeographical processes that shaped the genetic diversity of Scots pine in the Caucasus ecoregion and its probable future distribution under different climate scenarios. We found that the high genetic variability of the Caucasian populations mirrors a complex glacial and postglacial history that had a unique evolutionary trajectory compared to the main range in Europe. Scots pine currently grows under a broad spectrum of climatic conditions in the Caucasus, which implies high adaptive potential in the past. However, the current genetic resources of Scots pine are under high pressure from climate change. From our predictions, over 90% of the current distribution of Scots pine may be lost in this century. By threatening the stability of the forest ecosystems, this would dramatically affect the biodiversity of the Caucasus hot-spot.

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Stability and Folding of the Unusually Stable Hemoglobin from Synechocystis is Subtly Optimized and Dependent on the Key Heme Pocket Residues.

Protein and Peptide Letters ◽

10.2174/0929866527666200613220245 ◽

2020 ◽

Vol 27 ◽

Author(s):

Sheetal Uppal ◽

Mohd. Asim Khan ◽

Suman Kundu

Keyword(s):

Molten Globule ◽

Life Forms ◽

Model System ◽

Heme Pocket ◽

The Past ◽

Specific Manner ◽

Delivery Vehicles ◽

The Stability ◽

Key Residues ◽

Synechocystis Sp

Aims: The aim of our study is to understand the biophysical traits that govern the stability and folding of Synechocystis hemoglobin, a unique cyanobacterial globin that displays unusual traits not observed in any of the other globins discovered so far. Background: For the past few decades, classical hemoglobins such as vertebrate hemoglobin and myoglobin have been extensively studied to unravel the stability and folding mechanisms of hemoglobins. However, the expanding wealth of hemoglobins identified in all life forms with novel properties, like heme coordination chemistry and globin fold, have added complexity and challenges to the understanding of hemoglobin stability, which has not been adequately addressed. Here, we explored the unique truncated and hexacoordinate hemoglobin from the freshwater cyanobacterium Synechocystis sp. PCC 6803 known as “Synechocystis hemoglobin (SynHb)”. The “three histidines” linkages to heme are novel to this cyanobacterial hemoglobin. Objective: Mutational studies were employed to decipher the residues within the heme pocket that dictate the stability and folding of SynHb. Methods: Site-directed mutants of SynHb were generated and analyzed using a repertoire of spectroscopic and calorimetric tools. Result: The results revealed that the heme was stably associated to the protein under all denaturing conditions with His117 playing the anchoring role. The studies also highlighted the possibility of existence of a “molten globule” like intermediate at acidic pH in this exceptionally thermostable globin. His117 and other key residues in the heme pocket play an indispensable role in imparting significant polypeptide stability. Conclusion: Synechocystis hemoglobin presents an important model system for investigations of protein folding and stability in general. The heme pocket residues influenced the folding and stability of SynHb in a very subtle and specific manner and may have been optimized to make this Hb the most stable known as of date. Other: The knowledge gained hereby about the influence of heme pocket amino acid side chains on stability and expression is currently being utilized to improve the stability of recombinant human Hbs for efficient use as oxygen delivery vehicles.

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Copper Phyllosilicates-Derived Catalysts in the Production of Alcohols from Hydrogenation of Carboxylates, Carboxylic Acids, Carbonates, Formyls, and CO2: A Review

Catalysts ◽

10.3390/catal11020255 ◽

2021 ◽

Vol 11 (2) ◽

pp. 255

Author(s):

Dien-Thien To ◽

Yu-Chuan Lin

Keyword(s):

Carboxylic Acids ◽

Catalytic Performance ◽

Spatial Effect ◽

Synthesis Methods ◽

The Past ◽

Surface Areas ◽

Preparation Conditions ◽

Remedial Actions ◽

The Stability ◽

Size Interaction

Copper phyllosilicates-derived catalysts (CuPS-cats) have been intensively explored in the past two decades due to their promising activity in carbonyls hydrogenation. However, CuPS-cats have not been completely reviewed. This paper focuses on the aspects concerning CuPS-cats from synthesis methods, effects of preparation conditions, and dopant to catalytic applications of CuPS-cats. The applications of CuPS-cats include the hydrogenation of carboxylates, carboxylic acids, carbonates, formyls, and CO2 to their respective alcohols. Besides, important factors such as the Cu dispersion, Cu+ and Cu0 surface areas, particles size, interaction between Cu and supports and dopants, morphologies, and spatial effect on catalytic performance of CuPS-cats are discussed. The deactivation and remedial actions to improve the stability of CuPS-cats are summarized. It ends up with the challenges and prospective by using this type of catalyst.

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Change in mean and extreme temperature at Yingkou station in Northeast China from 1904 to 2017

Climatic Change ◽

10.1007/s10584-021-02981-w ◽

2021 ◽

Vol 164 (3-4) ◽

Author(s):

Xiaoying Xue ◽

Guoyu Ren ◽

Xiubao Sun ◽

Panfeng Zhang ◽

Yuyu Ren ◽

...

Keyword(s):

Northeast China ◽

Extreme Temperature ◽

Maximum Temperature ◽

Data Set ◽

The Past ◽

Significant Downward Trend ◽

Cold Events ◽

Temperature Indices ◽

Increasing Trends ◽

Change In Mean

AbstractThe understanding of centennial trends of extreme temperature has been impeded due to the lack of early-year observations. In this paper, we collect and digitize the daily temperature data set of Northeast China Yingkou meteorological station since 1904. After quality control and homogenization, we analyze the changes of mean and extreme temperature in the past 114 years. The results show that mean temperature (Tmean), maximum temperature (Tmax), and minimum temperature (Tmin) all have increasing trends during 1904–2017. The increase of Tmin is the most obvious with the rate of 0.34 °C/decade. The most significant warming occurs in spring and winter with the rate of Tmean reaching 0.32 °C/decade and 0.31 °C/decade, respectively. Most of the extreme temperature indices as defined using absolute and relative thresholds of Tmax and Tmin also show significant changes, with cold events witnessing a more significant downward trend. The change is similar to that reported for global land and China for the past six decades. It is also found that the extreme highest temperature (1958) and lowest temperature (1920) records all occurred in the first half of the whole period, and the change of extreme temperature indices before 1950 is different from that of the recent decades, in particular for diurnal temperature range (DTR), which shows an opposite trend in the two time periods.

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Thermodynamic and Energy Efficiency Analysis of a Domestic Refrigerator Using Al2O3 Nano-Refrigerant

Sustainability ◽

10.3390/su13105659 ◽

2021 ◽

Vol 13 (10) ◽

pp. 5659

Author(s):

Farhood Sarrafzadeh Javadi ◽

Rahman Saidur

Keyword(s):

Temperature Gradient ◽

Technological Changes ◽

Nanoparticle Concentration ◽

Evaporator Temperature ◽

Domestic Refrigerator ◽

The Past ◽

Nano Lubricant ◽

The Stability ◽

Energy Efficiency Analysis ◽

Al2o3 Nanofluid

Refrigeration systems have experienced massive technological changes in the past 50 years. Nanotechnology can lead to a promising technological leap in the refrigeration industry. Nano-refrigerant still remains unknown because of the complexity of the phase change process of the mixture including refrigerant, lubricant, and nanoparticle. In this study, the stability of Al2O3 nanofluid and the performance of a nano-refrigerant-based domestic refrigerator have been experimentally investigated, with the focus on the thermodynamic and energy approaches. It was found that by increasing the nanoparticle concentration, the stability of nano-lubricant was decreased and evaporator temperature gradient was increased. The average of the temperature gradient increment in the evaporator was 20.2% in case of using 0.1%-Al2O3. The results showed that the energy consumption of the refrigerator reduced around 2.69% when 0.1%-Al2O3 nanoparticle was added to the system.

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Trends and sociodemographic inequalities in the use of caesarean section in Indonesia, 1987-2017

BMJ Global Health ◽

10.1136/bmjgh-2020-003844 ◽

2020 ◽

Vol 5 (12) ◽

pp. e003844

Author(s):

Rana Islamiah Zahroh ◽

George Disney ◽

Ana Pilar Betrán ◽

Meghan A. Bohren

Keyword(s):

Caesarean Section ◽

Health Facility ◽

Rate Ratio ◽

Maternal Education ◽

Sociodemographic Characteristics ◽

Public And Private ◽

The Past ◽

Life Saving ◽

Facility Type ◽

Increasing Trends

IntroductionCaesarean section (CS) rates are increasing globally. CS can be a live-saving procedure when medically indicated, but it comes with higher risks for women and newborns when done without medical indication. Crucially, inequalities in who receives CS exist, both within and across countries. Understanding factors driving increasing rates and inequalities of CS is imperative to optimise the use of this life-saving intervention. This study aimed to investigate trends of CS use and inequalities across sociodemographic characteristics in Indonesia over a 30-year period.MethodsSeven waves of the Indonesia Demographic and Health Survey were used to estimate trends and inequalities in CS from 1987 to 2017. Relative and absolute inequalities across a range of sociodemographic characteristics were estimated and trends in inequalities were assessed through changes in rate ratio and rate difference.ResultsThe proportion of facility-based births in Indonesia has increased in the past 30 years, coinciding with an increase in CS rate (CSR) (1991 CSR: 1.6% (95% CI 1.3 to 1.9); 2017 CSR: 17.6% (95% CI 16.7 to 18.5)). Higher rates of CS are observed mostly in Western Indonesia, while lower CSRs are observed in Eastern Indonesia. Inequalities of CSRs in Indonesia are observed across type of health facility (public/private), regions, places of residence, wealth quintiles and maternal education, with the highest CSRs in more affluent and educated groups. Widening absolute inequalities of CS are observed across all sociodemographic characteristics, except facility type, where CSR gaps between public and private facilities have closed on both relative and absolute scales.ConclusionThis study provides evidence of increasing trends in CSRs and widening absolute inequalities in CSRs across different sociodemographic groups of women in Indonesia. The context of increasing CSRs across society, however, may have resulted in more stable relative inequalities. Improving understanding of the drivers of these trends in Indonesia and, particularly, of women’s and providers’ perspectives and preferences for childbirth, should be prioritised to optimise the use of CS.

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Projections of surface air temperature required to sustain permafrost and importance of adaptation to climate change in the Daisetsu Mountains, Japan

Scientific Reports ◽

10.1038/s41598-021-94222-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Tokuta Yokohata ◽

Go Iwahana ◽

Toshio Sone ◽

Kazuyuki Saito ◽

Noriko N. Ishizaki ◽

...

Keyword(s):

Climate Model ◽

Surface Air Temperature ◽

Climatic Conditions ◽

Alpine Ecosystems ◽

Adaptation To Climate Change ◽

Freezing And Thawing ◽

Air Temperatures ◽

Statistical Relationships ◽

The Stability ◽

Slope Displacement

AbstractPermafrost is known to occur in high mountainous areas such as the Daisetsu Mountains in Japan, which are located at the southernmost limit of the permafrost distribution in the world. In this study, areas with climatic conditions suitable for sustaining permafrost in the Daisetsu Mountains are projected using bias-corrected and downscaled climate model outputs and statistical relationships between surface air temperatures and permafrost areas. Using freezing and thawing indices, the size of the area in the Daisetsu Mountains where climatic conditions were suitable for permafrost were estimated to be approximately 150 km2 in 2010. Under the RCP8.5 scenario, this area is projected to decrease to about 30 km2 by 2050 and it is projected to disappear by around 2070. Under the RCP2.6 scenario, the area is projected to decrease to approximately 20 km2 by 2100. The degradation of mountain permafrost could potentially affect the stability of trekking trails due to slope displacement, and it may also have deleterious effects on current alpine ecosystems. It is therefore important to accurately monitor changes in the mountain ecosystem environment and to implement measures to adapt to an environment that is projected to change significantly in the future.

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Water confined in solutions of biological relevance

Pure and Applied Chemistry ◽

10.1515/pac-2019-1202 ◽

2020 ◽

Vol 92 (10) ◽

pp. 1563-1574

Author(s):

Marie-Claire Bellissent-Funel

Keyword(s):

Aqueous Solutions ◽

Bulk Water ◽

Biological Macromolecules ◽

Organic Solutes ◽

Confined Water ◽

The Past ◽

Structure And Dynamics ◽

Biological Relevance ◽

The Stability

AbstractIn many relevant situations, water is not in its bulk form but instead attached to some substrates or filling some cavities. We shall call water in the latter environment confined water as opposed to bulk water. It is known that the confined water is essential for the stability and the function of biological macromolecules. In this paper, we provide a review of the experimental and computational advances over the past decades concerning the understanding of the structure and dynamics of water confined in aqueous solutions of biological relevance. Examples involving water in solution of organic solutes (cryoprotectants such as dimethylsulfoxide (DMSO), sugars such as trehalose) are provided.

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