The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that ope...The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.展开更多
The Pearl River Estuary(PRE) is located at the onshore-offshore transition zone between South China and South China Sea Basin, and it is of great significant value in discussing tectonic relationships between South Ch...The Pearl River Estuary(PRE) is located at the onshore-offshore transition zone between South China and South China Sea Basin, and it is of great significant value in discussing tectonic relationships between South China block and South China Sea block and seismic activities along the offshore active faults in PRE. However, the researches on geometric characteristics of offshore faults in this area are extremely lacking. To investigate the offshore fault distribution and their geometric features in the PRE in greater detail, we acquired thirteen seismic reflection profiles in 2015. Combining the analysis of the seismic reflection and free-air gravity anomaly data, this paper revealed the location, continuity, and geometry of the littoral fault zone and other offshore faults in PRE. The littoral fault zone is composed of the major Dangan Islands fault and several parallel, high-angle, normal faults, which mainly trend northeast to northeast-to-east and dip to the southeast with large displacements. The fault zone is divided into three different segments by the northwest-trending faults. Moreover, the basement depth around Dangan Islands is very shallow, while it suddenly increases along the islands westward and southward. These has resulted in the islands and neighboring areas becoming the places where the stress accumulates easily. The seismogenic pattern of this area is closely related to the comprehensive effect of intersecting faults together with the low velocity layer.展开更多
Lake littoral zones are characterized by heterogeneity in the biogeochemistry of nutrient elements. This study aimed to explore the relationship between the nitrous oxide reductase gene （nosZ）-encoding denitrifier c...Lake littoral zones are characterized by heterogeneity in the biogeochemistry of nutrient elements. This study aimed to explore the relationship between the nitrous oxide reductase gene （nosZ）-encoding denitrifier community composition/abundance and N2O reduction. Five samples （deep sediment, near-transition sediment, transition site, near-transition land and land soil） were collected along a littoral gradient of eutrophic Baiyangdian Lake, North China. To investigate the relationship between the nosZ-encoding denitrifier community structure and N20 reduction, the nosZ-encoding denitrifier community composition/abundance, potential denitrification rate （DNR） and potential N20 production rate （pN20） were investigated using molecular biological technologies and laboratory incubation experiments. The results showed that the average DNR of sediments was about 25 times higher than that of land soils, reaching 282.5 nmol N/（g dry weight （dw）.hr） and that the average pN20 of sediments was about 3.5 times higher than that of land soils, reaching 15.7 nmol N/（g dw-hr）. In the land area, the nosZ gene abundance showed a negative correlation with the N20/（N20＋N2） ratio, indicating that nosZ gene abundance dominated N20 reduction both in the surface soils of the land area and in the soil core of the transition site. Phylogenetic analysis showed that all the nosZ sequences recovered from sediment clustered closely with the isolates Azospirillum largimobile and Azospirillum irakense affiliated to Rhodospirillaceae in alpha-Proteobacteria, while about 92.3% （12/13） of the nosZ sequences recovered from land soil affiliated to Rhizobiaceae and Bradyrhizobiaceae in a-Proteobacteria. The community composition of nosZ gene-encoding denitrifiers appeared to be coupled with N20 reduction along the littoral gradient.展开更多
The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers （AOA and AOB） were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot ...The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers （AOA and AOB） were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot for N cycling. Here we found high spatial heterogeneity in the nitrification rate and abundance of ammonia oxidizers in the five sampling sites. The bacterial amoA gene was numerically dominant in most of the surface soil but decreased dramatically in deep layers. Higher nitrification potentials were detected in two sites near the land/water interface at 4.4–6.1 μg NO2-N/（g dry weight soil·hr）, while only 1.0–1.7 μg NO2-N/（g dry weight soil·hr） was measured at other sites. The potential nitrification rates were proportional to the amoA gene abundance for AOB, but with no significant correlation with AOA. The NH4＋ concentration was the most determinative parameter for the abundance of AOB and potential nitrification rates in this study. Higher richness in the surface layer was found in the analysis of biodiversity. Phylogenetic analysis revealed that most of the bacterial amoA sequences in surface soil were affiliated with the genus of Nitrosopira while the archaeal sequences were almost equally affiliated with Candidatus ‘Nitrososphaera gargensis’ and Candidatus ‘Nitrosocaldus yellowstonii’. The spatial distribution of AOA and AOB indicated that bacteria may play a more important role in nitrification in the littoral buffer zone of a N-rich lake.展开更多
Introduction: Food security is one of the greatest challenges that most African countries face. It is a concept that considers not only food quantity but also food quality. The objective of this study was to describe ...Introduction: Food security is one of the greatest challenges that most African countries face. It is a concept that considers not only food quantity but also food quality. The objective of this study was to describe dietary diversity and food security status at the individual level in Cameroonian populations. Methods: A total of 1180 men and women aged 20 and over and living in the West, North West, and Littoral regions of Cameroon were recruited. Data on dietary habits were collected through the frequency of consumption of various food groups. Dietary diversity was assessed using a 24-hour dietary recall. Food security status was determined by combining two indicators (food consumption score and individual food diversity score). Results: The mean dietary diversity score of the population was 3.53 ± 1.44, p Conclusion: The diet diversity of adults living in the West, North West, and Littoral regions of Cameroon is medium. Although half of the study population was food secure, there is a need to implement food security policies further to reduce food insecurity among the Cameroonian population.展开更多
Introduction: The number of people suffering from diabetes and hypertension (HBP) is increasing worldwide and particularly in sub-Saharan Africa, despite the fact that they are preventable. The aim of our study is to ...Introduction: The number of people suffering from diabetes and hypertension (HBP) is increasing worldwide and particularly in sub-Saharan Africa, despite the fact that they are preventable. The aim of our study is to determine the factors associated with hypertension and diabetes comorbidity in the Department of Littoral in 2023. Study Setting and Methods: Our study took place in the Department of Littoral in Benin. It was a cross-sectional general population study conducted over a three-month period from April 10 to July 10, 2023. It included subjects aged 18 and over with or without a history of hypertension and/or diabetes. The sampling method was probabilistic and the technique used was a WHO three-stage cluster survey. The dependent variable is comorbidity of hypertension and diabetes. A logistic regression model was used to identify factors associated with hypertension-diabetes comorbidity. Results: The study population was predominantly female (59.9%). The mean age was 44 ± 17. A total of 48 (8.8%) of the subjects in the study suffered from both diabetes and hypertension. Factors associated with comorbidity of hypertension and diabetes were age ≥ 50 years (OR: 5.48;95% CI: 2.69 - 12.20;p = 0.001);male sex (OR: 2.98;95% CI: 1.39 - 6.46;p = 0.005);too much salt or salty sauce consumed (OR: 6.06;95% CI: 1.56 - 22.20;p = 0.034);abdominal obesity (OR: 6.12;95% CI: 2.79 - 14.3;p = 0.001). Conclusion: Hypertension and diabetes are emerging as major public health problems in Benin. The main associated factors were age, gender, the amount of salt or salty sauce consumed and abdominal obesity. A response is urgently needed to act on the factors identified in order to avoid possible complications and an increase in prevalence.展开更多
Littoral cell angioma is a recently described rare vascular tumor of the spleen. The clinical course of this benign tumor is asymptomatic in most patients. Herein, we described three patients with littoral cell angiom...Littoral cell angioma is a recently described rare vascular tumor of the spleen. The clinical course of this benign tumor is asymptomatic in most patients. Herein, we described three patients with littoral cell angioma detected during physical examination. A brief discussion and review of a handful of cases of splenic littoral cell angioma, which have been previously reported in the English language literature, are performed in this PaPer.展开更多
AIM:To establish the safety and feasibility of laparoscopic splenectomy(LS) for littoral cell angioma(LCA).METHODS:From September 2003 to November 2013,27 patients were diagnosed with LCA in our institution.These pati...AIM:To establish the safety and feasibility of laparoscopic splenectomy(LS) for littoral cell angioma(LCA).METHODS:From September 2003 to November 2013,27 patients were diagnosed with LCA in our institution.These patients were divided into two groups based on operative procedure:LS(13 cases,Group 1) and open splenectomy(14 cases,Group 2).Data were collected retrospectively by chart review.Comparisons were performed between the two groups in terms of demographic characteristics(sex and age); operative outcomes(operative time,estimated blood loss,transfusion,and conversion); postoperative details(length of postoperative stay and complications); and follow-up outcome.RESULTS:LS was successfully carried out in all patients except one in Group 1,who required conversion to hand-assisted LS because of perisplenic adhesions.The average operative time for patients in Group 1 was significantly shorter than that in Group 2(127 ± 34 min vs 177 ± 25 min,P = 0.001).The average estimated blood loss in Group 1 was significantly lower than in Group 2(62 ± 48 m L vs 138 ± 64 m L,P < 0.01).No patient in Group 1 required a blood transfusion,whereas one in Group 2 required a transfusion.Two patients in Group 1 and four in Group 2 suffered from postoperative complications.All the complications were cured by conservative therapy.There were no deaths in our series.All patients were followed up and no recurrence or abdominal metastasis were found.CONCLUSION:LS for patients with LCA is safe and feasible,with preferable operative outcomes and longterm tumor-free survival.展开更多
Primary splenic lesions are rare entities among which littoral cell angioma(LCA) is a recently described, uncommon vascular lesion that is unique to the spleen. It has heretofore been described primarily in pathologic...Primary splenic lesions are rare entities among which littoral cell angioma(LCA) is a recently described, uncommon vascular lesion that is unique to the spleen. It has heretofore been described primarily in pathologic series and has been found mostly to behave as a benign entity. A few reports of malignant variants have been reported. We present a case report of a solitary LCA discovered after splenectomy for an incidentally discovered splenic lesion, along with a literature review.展开更多
基金Research Fund from Science and Technology on Underwater Vehicle Laboratory
文摘The navy and other Department of Defense organizations are increasingly interested in the use of unmanned surface vehicles (USVs) for a variety of missions and applications. The term USV refers to any vehicle that operates on the surface of the water without a crew. USVs have the potential, and in some cases the demonstrated ability, to reduce risk to manned forces, provide the necessary force multiplication to accomplish military missions, perform tasks which manned vehicles cannot, and do so in a way that is affordable for the navy. A survey of USV activities worldwide as well as the general technical challenges of USVs was presented below. A general description of USVs was provided along with their typical applications. The technical challenges of developing a USV include its intelligence level, control, high stability, and developmental cost reduction. Through the joint efforts of researchers around the world, it is believed that the development of USVs will enter a new phase in the near future, as USVs could soon be applied widely both in military and civilian service.
基金supported by the National Natural Science Foundation of China(Nos.41506046,41376060,41706054)the Opening Foundation of Key Laboratory of Ocean and Marginal Sea Geology,CAS(No.MSGL15-05)+1 种基金WPOS(No.XDA11030102-02)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDA13010101)
文摘The Pearl River Estuary(PRE) is located at the onshore-offshore transition zone between South China and South China Sea Basin, and it is of great significant value in discussing tectonic relationships between South China block and South China Sea block and seismic activities along the offshore active faults in PRE. However, the researches on geometric characteristics of offshore faults in this area are extremely lacking. To investigate the offshore fault distribution and their geometric features in the PRE in greater detail, we acquired thirteen seismic reflection profiles in 2015. Combining the analysis of the seismic reflection and free-air gravity anomaly data, this paper revealed the location, continuity, and geometry of the littoral fault zone and other offshore faults in PRE. The littoral fault zone is composed of the major Dangan Islands fault and several parallel, high-angle, normal faults, which mainly trend northeast to northeast-to-east and dip to the southeast with large displacements. The fault zone is divided into three different segments by the northwest-trending faults. Moreover, the basement depth around Dangan Islands is very shallow, while it suddenly increases along the islands westward and southward. These has resulted in the islands and neighboring areas becoming the places where the stress accumulates easily. The seismogenic pattern of this area is closely related to the comprehensive effect of intersecting faults together with the low velocity layer.
基金supported by the National Natural Science Foundation of China (No.21077119)the National Basic Research Program of China(No. 2009CB421103)+3 种基金the Key Project of Water Pollution Control and Management of China (No.2008ZX07209-006, 2009ZX07209-005 and 2008ZX07421-001)the Special Fund of Tianjin Science and Technology Innovation Project (No. 08FDZDSF03200)the support of the Beijing Nova Program (No. 2011095)the K. C. Wong Education Foundation, Hong Kong, China
文摘Lake littoral zones are characterized by heterogeneity in the biogeochemistry of nutrient elements. This study aimed to explore the relationship between the nitrous oxide reductase gene （nosZ）-encoding denitrifier community composition/abundance and N2O reduction. Five samples （deep sediment, near-transition sediment, transition site, near-transition land and land soil） were collected along a littoral gradient of eutrophic Baiyangdian Lake, North China. To investigate the relationship between the nosZ-encoding denitrifier community structure and N20 reduction, the nosZ-encoding denitrifier community composition/abundance, potential denitrification rate （DNR） and potential N20 production rate （pN20） were investigated using molecular biological technologies and laboratory incubation experiments. The results showed that the average DNR of sediments was about 25 times higher than that of land soils, reaching 282.5 nmol N/（g dry weight （dw）.hr） and that the average pN20 of sediments was about 3.5 times higher than that of land soils, reaching 15.7 nmol N/（g dw-hr）. In the land area, the nosZ gene abundance showed a negative correlation with the N20/（N20＋N2） ratio, indicating that nosZ gene abundance dominated N20 reduction both in the surface soils of the land area and in the soil core of the transition site. Phylogenetic analysis showed that all the nosZ sequences recovered from sediment clustered closely with the isolates Azospirillum largimobile and Azospirillum irakense affiliated to Rhodospirillaceae in alpha-Proteobacteria, while about 92.3% （12/13） of the nosZ sequences recovered from land soil affiliated to Rhizobiaceae and Bradyrhizobiaceae in a-Proteobacteria. The community composition of nosZ gene-encoding denitrifiers appeared to be coupled with N20 reduction along the littoral gradient.
基金supported by the National Natural Science Foundation of China (No. 20877086 21077119)+5 种基金the National Basic Research Program (973) of China (No. 2009CB421103)the National Water Project of China (No. 2009ZX07209-005 2008ZX07421-001 2008ZX07209-006-02)the support of Beijing Nova Program (No. 2011104)K. C. Wong Education Foundation, Hong Kong
文摘The spatial distribution and diversity of archaeal and bacterial ammonia oxidizers （AOA and AOB） were evaluated targeting amoA genes in the gradient of a littoral buffer zone which has been identified as a hot spot for N cycling. Here we found high spatial heterogeneity in the nitrification rate and abundance of ammonia oxidizers in the five sampling sites. The bacterial amoA gene was numerically dominant in most of the surface soil but decreased dramatically in deep layers. Higher nitrification potentials were detected in two sites near the land/water interface at 4.4–6.1 μg NO2-N/（g dry weight soil·hr）, while only 1.0–1.7 μg NO2-N/（g dry weight soil·hr） was measured at other sites. The potential nitrification rates were proportional to the amoA gene abundance for AOB, but with no significant correlation with AOA. The NH4＋ concentration was the most determinative parameter for the abundance of AOB and potential nitrification rates in this study. Higher richness in the surface layer was found in the analysis of biodiversity. Phylogenetic analysis revealed that most of the bacterial amoA sequences in surface soil were affiliated with the genus of Nitrosopira while the archaeal sequences were almost equally affiliated with Candidatus ‘Nitrososphaera gargensis’ and Candidatus ‘Nitrosocaldus yellowstonii’. The spatial distribution of AOA and AOB indicated that bacteria may play a more important role in nitrification in the littoral buffer zone of a N-rich lake.
文摘Introduction: Food security is one of the greatest challenges that most African countries face. It is a concept that considers not only food quantity but also food quality. The objective of this study was to describe dietary diversity and food security status at the individual level in Cameroonian populations. Methods: A total of 1180 men and women aged 20 and over and living in the West, North West, and Littoral regions of Cameroon were recruited. Data on dietary habits were collected through the frequency of consumption of various food groups. Dietary diversity was assessed using a 24-hour dietary recall. Food security status was determined by combining two indicators (food consumption score and individual food diversity score). Results: The mean dietary diversity score of the population was 3.53 ± 1.44, p Conclusion: The diet diversity of adults living in the West, North West, and Littoral regions of Cameroon is medium. Although half of the study population was food secure, there is a need to implement food security policies further to reduce food insecurity among the Cameroonian population.
文摘Introduction: The number of people suffering from diabetes and hypertension (HBP) is increasing worldwide and particularly in sub-Saharan Africa, despite the fact that they are preventable. The aim of our study is to determine the factors associated with hypertension and diabetes comorbidity in the Department of Littoral in 2023. Study Setting and Methods: Our study took place in the Department of Littoral in Benin. It was a cross-sectional general population study conducted over a three-month period from April 10 to July 10, 2023. It included subjects aged 18 and over with or without a history of hypertension and/or diabetes. The sampling method was probabilistic and the technique used was a WHO three-stage cluster survey. The dependent variable is comorbidity of hypertension and diabetes. A logistic regression model was used to identify factors associated with hypertension-diabetes comorbidity. Results: The study population was predominantly female (59.9%). The mean age was 44 ± 17. A total of 48 (8.8%) of the subjects in the study suffered from both diabetes and hypertension. Factors associated with comorbidity of hypertension and diabetes were age ≥ 50 years (OR: 5.48;95% CI: 2.69 - 12.20;p = 0.001);male sex (OR: 2.98;95% CI: 1.39 - 6.46;p = 0.005);too much salt or salty sauce consumed (OR: 6.06;95% CI: 1.56 - 22.20;p = 0.034);abdominal obesity (OR: 6.12;95% CI: 2.79 - 14.3;p = 0.001). Conclusion: Hypertension and diabetes are emerging as major public health problems in Benin. The main associated factors were age, gender, the amount of salt or salty sauce consumed and abdominal obesity. A response is urgently needed to act on the factors identified in order to avoid possible complications and an increase in prevalence.
文摘Littoral cell angioma is a recently described rare vascular tumor of the spleen. The clinical course of this benign tumor is asymptomatic in most patients. Herein, we described three patients with littoral cell angioma detected during physical examination. A brief discussion and review of a handful of cases of splenic littoral cell angioma, which have been previously reported in the English language literature, are performed in this PaPer.
文摘AIM:To establish the safety and feasibility of laparoscopic splenectomy(LS) for littoral cell angioma(LCA).METHODS:From September 2003 to November 2013,27 patients were diagnosed with LCA in our institution.These patients were divided into two groups based on operative procedure:LS(13 cases,Group 1) and open splenectomy(14 cases,Group 2).Data were collected retrospectively by chart review.Comparisons were performed between the two groups in terms of demographic characteristics(sex and age); operative outcomes(operative time,estimated blood loss,transfusion,and conversion); postoperative details(length of postoperative stay and complications); and follow-up outcome.RESULTS:LS was successfully carried out in all patients except one in Group 1,who required conversion to hand-assisted LS because of perisplenic adhesions.The average operative time for patients in Group 1 was significantly shorter than that in Group 2(127 ± 34 min vs 177 ± 25 min,P = 0.001).The average estimated blood loss in Group 1 was significantly lower than in Group 2(62 ± 48 m L vs 138 ± 64 m L,P < 0.01).No patient in Group 1 required a blood transfusion,whereas one in Group 2 required a transfusion.Two patients in Group 1 and four in Group 2 suffered from postoperative complications.All the complications were cured by conservative therapy.There were no deaths in our series.All patients were followed up and no recurrence or abdominal metastasis were found.CONCLUSION:LS for patients with LCA is safe and feasible,with preferable operative outcomes and longterm tumor-free survival.
文摘Primary splenic lesions are rare entities among which littoral cell angioma(LCA) is a recently described, uncommon vascular lesion that is unique to the spleen. It has heretofore been described primarily in pathologic series and has been found mostly to behave as a benign entity. A few reports of malignant variants have been reported. We present a case report of a solitary LCA discovered after splenectomy for an incidentally discovered splenic lesion, along with a literature review.
