The health systems in many countries are still unable to control the evolution and persistence of the COVID-19 pandemic despite the large mobilisation of national resources. International attention has focussed on finding a cure, and preventive measures and national and international strategies to be adopted and implemented with regard to other future pandemics have been neglected despite their predictability and high probability of occurrence. This work aims to anticipate a reading on experience feedback in light of the current pandemic situation, and to identify the main spatial elements of vulnerability in Batna, Algeria, which seems to control the ability of an urban area to prevent the spread of the COVID-19 virus. We used a digital model based on a multi-criteria approach implemented in a geo-decisional GIS database to serve as a decision support tool for dealing with an epidemiological situation as a preventive or curative action. The results from the model seem to adequately reflect the reality of confirmed incidents in Batna. In addition, the results of the analysis of the spatiotemporal evolution of the virus clearly confirm that the urban sectors characterised by high vulnerability are those that have recorded an increasing number of confirmed COVID-19 incidents since the start of the epidemic until December 2020.

Let A, A_{1},  A_{2}, B, B_{1}, B_{2}, C_{1} and C_{2} be linear bounded operators on Hilbert spaces. In this paper, by using generalized inverses, we establish necessary and sufficient conditions for the existence of a common solution and give the form of the general common solution of the operator equations A_{1}XB_{1}=C_{1} and A_{2}XB_{2}=C_{2}, we apply this result to determine new necessary and sufficient conditions for the existence of Hermitian solutions  and give the form of the general Hermitian solution to the operator equation AXB=C. As a consequence, we give necessary and sufficient condition for the existence of Hermitian solution to the operator equation AXA^{*}+BYB^{*}=C.

Let A, A_{1},  A_{2}, B, B_{1}, B_{2}, C_{1} and C_{2} be linear bounded operators on Hilbert spaces. In this paper, by using generalized inverses, we establish necessary and sufficient conditions for the existence of a common solution and give the form of the general common solution of the operator equations A_{1}XB_{1}=C_{1} and A_{2}XB_{2}=C_{2}, we apply this result to determine new necessary and sufficient conditions for the existence of Hermitian solutions  and give the form of the general Hermitian solution to the operator equation AXB=C. As a consequence, we give necessary and sufficient condition for the existence of Hermitian solution to the operator equation AXA^{*}+BYB^{*}=C.

In wireless sensor networks (WSNs), multi-channel communication represents an attractive field due to its advantage in improving throughput and delivery rate. However, the major challenge that faces WSNs is the energy constraint. To overcome the channel assignment problem in an energy-efficient way, reinforcement learning (RL) approach is used. Though, RL requires several iterations to obtain the best solution, creating a communication overhead and time-wasting. In this paper, a heuristically accelerated reinforcement learning approach for channel assignment (HARL CA) in WSNs is proposed to reduce the learning iterations. The proposal considers the selected channel by the neighboring sender nodes as external information, used to accelerate the learning process and to avoid collisions, while the bandwidth of the used channel is regarded as an important factor in the scheduling process to increase the delivery rate. The results of extensive simulation experiments show the effectiveness of our approach in improving the network lifetime and performance.

In wireless sensor networks (WSNs), multi-channel communication represents an attractive field due to its advantage in improving throughput and delivery rate. However, the major challenge that faces WSNs is the energy constraint. To overcome the channel assignment problem in an energy-efficient way, reinforcement learning (RL) approach is used. Though, RL requires several iterations to obtain the best solution, creating a communication overhead and time-wasting. In this paper, a heuristically accelerated reinforcement learning approach for channel assignment (HARL CA) in WSNs is proposed to reduce the learning iterations. The proposal considers the selected channel by the neighboring sender nodes as external information, used to accelerate the learning process and to avoid collisions, while the bandwidth of the used channel is regarded as an important factor in the scheduling process to increase the delivery rate. The results of extensive simulation experiments show the effectiveness of our approach in improving the network lifetime and performance.

In wireless sensor networks (WSNs), multi-channel communication represents an attractive field due to its advantage in improving throughput and delivery rate. However, the major challenge that faces WSNs is the energy constraint. To overcome the channel assignment problem in an energy-efficient way, reinforcement learning (RL) approach is used. Though, RL requires several iterations to obtain the best solution, creating a communication overhead and time-wasting. In this paper, a heuristically accelerated reinforcement learning approach for channel assignment (HARL CA) in WSNs is proposed to reduce the learning iterations. The proposal considers the selected channel by the neighboring sender nodes as external information, used to accelerate the learning process and to avoid collisions, while the bandwidth of the used channel is regarded as an important factor in the scheduling process to increase the delivery rate. The results of extensive simulation experiments show the effectiveness of our approach in improving the network lifetime and performance.

The design and the evaluation of communication protocols in WSNs is a crucial issue. Generally, researchers use simulation methods to evaluate them. However, formal modelling and analysis techniques are an efficient alternative to simulation methods. Indeed, these techniques allow performance evaluation and model verification. In this paper, a formal approach is proposed to modelling and to evaluating the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) MAC protocol with a star topology. Moreover, the proposed approach deals with some properties that are not stated in most existing works. The approach uses Hierarchical Timed Coloured Petri Nets (HTCPNs) formalism to model the protocol and exploits the CPN-Tools to analyse the generated models. HTCPNs provide timed aspect which facilitates the consideration of time constraints inherent to the CSMA/CA protocol.

The design and the evaluation of communication protocols in WSNs is a crucial issue. Generally, researchers use simulation methods to evaluate them. However, formal modelling and analysis techniques are an efficient alternative to simulation methods. Indeed, these techniques allow performance evaluation and model verification. In this paper, a formal approach is proposed to modelling and to evaluating the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) MAC protocol with a star topology. Moreover, the proposed approach deals with some properties that are not stated in most existing works. The approach uses Hierarchical Timed Coloured Petri Nets (HTCPNs) formalism to model the protocol and exploits the CPN-Tools to analyse the generated models. HTCPNs provide timed aspect which facilitates the consideration of time constraints inherent to the CSMA/CA protocol.

The design and the evaluation of communication protocols in WSNs is a crucial issue. Generally, researchers use simulation methods to evaluate them. However, formal modelling and analysis techniques are an efficient alternative to simulation methods. Indeed, these techniques allow performance evaluation and model verification. In this paper, a formal approach is proposed to modelling and to evaluating the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) MAC protocol with a star topology. Moreover, the proposed approach deals with some properties that are not stated in most existing works. The approach uses Hierarchical Timed Coloured Petri Nets (HTCPNs) formalism to model the protocol and exploits the CPN-Tools to analyse the generated models. HTCPNs provide timed aspect which facilitates the consideration of time constraints inherent to the CSMA/CA protocol.

The design and the evaluation of communication protocols in WSNs is a crucial issue. Generally, researchers use simulation methods to evaluate them. However, formal modelling and analysis techniques are an efficient alternative to simulation methods. Indeed, these techniques allow performance evaluation and model verification. In this paper, a formal approach is proposed to modelling and to evaluating the Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) MAC protocol with a star topology. Moreover, the proposed approach deals with some properties that are not stated in most existing works. The approach uses Hierarchical Timed Coloured Petri Nets (HTCPNs) formalism to model the protocol and exploits the CPN-Tools to analyse the generated models. HTCPNs provide timed aspect which facilitates the consideration of time constraints inherent to the CSMA/CA protocol.

The objective of this study was to evaluate the effect of food supply in garbage dumps on the reproductive fitness of Cattle Egret Bubulcus ibis and offspring losses. A total of 236 nests were monitored during two distinct periods of 2 years for each: 146 nests during a period without food supply in dumps (1998–1999) and 90 with food supply in dumps (2007–2008). The study was carried out in the colony of El-Kseur in the Lower Soummam Valley (northeast Algeria). For the entire study period, the mean of clutch size, average number of hatched chicks, productivity, and breeding success varied significantly between years (Kruskal–Wallis test: p < .05). Also, the average calculated losses for eggs, chicks, and total offspring vary significantly (Chi2 test: p > .0001). The clutch size and the number of hatched chicks per nest were highest during the period with food supply in garbage dump (respectively: 3.46 ± 0.86; 2.85 ± 1.11), compared to the period when cattle egrets feed in natural or agricultural habitats (3.04 ± 0.87; 2.54 ± 1.03). However, productivity and breeding success were highest during the period without food supply (respectively: 2.11 ± 1.16 fledging’s/nest; 0.70 ± 0.35) than in the period with food supply (1.14 ± 0.91; 0.35 ± 0.30). While egg losses were substantially similar between the two study periods, chick’s mortality (59.9%) and total offspring losses (36.7%) were higher during the period with food supply. The generalized linear mixed model (GLMM) analysis indicated a large negative effect of food supply in dumps on the productivity, on the chick’s losses; and a positive effect on the total offspring losses (p < .001). Also, feed in dump garbage revealed a significant negative effect on the breeding success linear mixed model (LMM, p = .01). However, no significant effects (GLMM, p > .05) of food supply in dumps were noted on average clutch size, the mean number of hatched chicks per nest, and egg losses.

The objective of this study was to evaluate the effect of food supply in garbage dumps on the reproductive fitness of Cattle Egret Bubulcus ibis and offspring losses. A total of 236 nests were monitored during two distinct periods of 2 years for each: 146 nests during a period without food supply in dumps (1998–1999) and 90 with food supply in dumps (2007–2008). The study was carried out in the colony of El-Kseur in the Lower Soummam Valley (northeast Algeria). For the entire study period, the mean of clutch size, average number of hatched chicks, productivity, and breeding success varied significantly between years (Kruskal–Wallis test: p < .05). Also, the average calculated losses for eggs, chicks, and total offspring vary significantly (Chi2 test: p > .0001). The clutch size and the number of hatched chicks per nest were highest during the period with food supply in garbage dump (respectively: 3.46 ± 0.86; 2.85 ± 1.11), compared to the period when cattle egrets feed in natural or agricultural habitats (3.04 ± 0.87; 2.54 ± 1.03). However, productivity and breeding success were highest during the period without food supply (respectively: 2.11 ± 1.16 fledging’s/nest; 0.70 ± 0.35) than in the period with food supply (1.14 ± 0.91; 0.35 ± 0.30). While egg losses were substantially similar between the two study periods, chick’s mortality (59.9%) and total offspring losses (36.7%) were higher during the period with food supply. The generalized linear mixed model (GLMM) analysis indicated a large negative effect of food supply in dumps on the productivity, on the chick’s losses; and a positive effect on the total offspring losses (p < .001). Also, feed in dump garbage revealed a significant negative effect on the breeding success linear mixed model (LMM, p = .01). However, no significant effects (GLMM, p > .05) of food supply in dumps were noted on average clutch size, the mean number of hatched chicks per nest, and egg losses.

The objective of this study was to evaluate the effect of food supply in garbage dumps on the reproductive fitness of Cattle Egret Bubulcus ibis and offspring losses. A total of 236 nests were monitored during two distinct periods of 2 years for each: 146 nests during a period without food supply in dumps (1998–1999) and 90 with food supply in dumps (2007–2008). The study was carried out in the colony of El-Kseur in the Lower Soummam Valley (northeast Algeria). For the entire study period, the mean of clutch size, average number of hatched chicks, productivity, and breeding success varied significantly between years (Kruskal–Wallis test: p < .05). Also, the average calculated losses for eggs, chicks, and total offspring vary significantly (Chi2 test: p > .0001). The clutch size and the number of hatched chicks per nest were highest during the period with food supply in garbage dump (respectively: 3.46 ± 0.86; 2.85 ± 1.11), compared to the period when cattle egrets feed in natural or agricultural habitats (3.04 ± 0.87; 2.54 ± 1.03). However, productivity and breeding success were highest during the period without food supply (respectively: 2.11 ± 1.16 fledging’s/nest; 0.70 ± 0.35) than in the period with food supply (1.14 ± 0.91; 0.35 ± 0.30). While egg losses were substantially similar between the two study periods, chick’s mortality (59.9%) and total offspring losses (36.7%) were higher during the period with food supply. The generalized linear mixed model (GLMM) analysis indicated a large negative effect of food supply in dumps on the productivity, on the chick’s losses; and a positive effect on the total offspring losses (p < .001). Also, feed in dump garbage revealed a significant negative effect on the breeding success linear mixed model (LMM, p = .01). However, no significant effects (GLMM, p > .05) of food supply in dumps were noted on average clutch size, the mean number of hatched chicks per nest, and egg losses.

The objective of this study was to evaluate the effect of food supply in garbage dumps on the reproductive fitness of Cattle Egret Bubulcus ibis and offspring losses. A total of 236 nests were monitored during two distinct periods of 2 years for each: 146 nests during a period without food supply in dumps (1998–1999) and 90 with food supply in dumps (2007–2008). The study was carried out in the colony of El-Kseur in the Lower Soummam Valley (northeast Algeria). For the entire study period, the mean of clutch size, average number of hatched chicks, productivity, and breeding success varied significantly between years (Kruskal–Wallis test: p < .05). Also, the average calculated losses for eggs, chicks, and total offspring vary significantly (Chi2 test: p > .0001). The clutch size and the number of hatched chicks per nest were highest during the period with food supply in garbage dump (respectively: 3.46 ± 0.86; 2.85 ± 1.11), compared to the period when cattle egrets feed in natural or agricultural habitats (3.04 ± 0.87; 2.54 ± 1.03). However, productivity and breeding success were highest during the period without food supply (respectively: 2.11 ± 1.16 fledging’s/nest; 0.70 ± 0.35) than in the period with food supply (1.14 ± 0.91; 0.35 ± 0.30). While egg losses were substantially similar between the two study periods, chick’s mortality (59.9%) and total offspring losses (36.7%) were higher during the period with food supply. The generalized linear mixed model (GLMM) analysis indicated a large negative effect of food supply in dumps on the productivity, on the chick’s losses; and a positive effect on the total offspring losses (p < .001). Also, feed in dump garbage revealed a significant negative effect on the breeding success linear mixed model (LMM, p = .01). However, no significant effects (GLMM, p > .05) of food supply in dumps were noted on average clutch size, the mean number of hatched chicks per nest, and egg losses.

Introduction: Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine. Objective: To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods: The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF). Results: 13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards. Conclusion: This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.

Introduction: Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine. Objective: To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods: The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF). Results: 13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards. Conclusion: This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.

Introduction: Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine. Objective: To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods: The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF). Results: 13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards. Conclusion: This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.

Introduction: Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine. Objective: To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods: The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF). Results: 13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards. Conclusion: This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.

Introduction: Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine. Objective: To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods: The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF). Results: 13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards. Conclusion: This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.

Introduction: Traditional medicine has an important place in human history and this since antiquity. Indeed, during Egyptian and Chinese civilization era, many detailed manuscripts, describing the therapeutic effect of plants, were found which suggest that folk medicine is the basis of the actual medicine. Objective: To investigate the phytochemical and pharmacological properties of the n-butanol (n-BuOH) and ethyl acetate (EA) extracts of the aerial part of Centaurea tougourensis. Methods: The phytochemical evaluation was done based on HPLC-DAD approach. The antioxidant activity was determined by DPPH and cupric ion reducing antioxidant capacity (CUPRAC), while the hemostatic effect was performed using plasma recalcification time (PRT) method. The antidiabetic capacity was investigated by alpha-amylase inhibition assay and the photoprotective test was evaluated by the measurement of sun protection factor (SPF). Results: 13 phenolic compounds were identified in both extracts of C. tougourensis. These extracts showed antioxidant, haemostatic, antidiabetic and photoprotective properties with a dose-dependent manner. Amounts of n-BuOH activities were found higher, with a respective IC50 value of 0.72±0.07 μg/ml in DPPH assay, an A0.50 value lower than 3.125 μg/ml in CUPRAC assay besides a shortening rate percentage of coagulation (86.71%) in haemostatic assay, a moderate inhibition effect on alpha amylase activity with an IC50 value of (711.5±0.03 μg/ml) and a maximum sun protection factor of (56.035). These results were mostly found highly significant (p<0.001) when compared to respective standards. Conclusion: This study demonstrated some pharmacological effects of C. tougourensis which suggests that our plant could be a good candidate to treat some illnesses related to oxidative stress, bleeding or skin cancer.