On the Four Eras of the Use of the Ocean by Mankind

This paper takes the relationship between humans and the ocean as the object of analysis, from the perspective of human use of the ocean, four era theories on the relationship between humans and the ocean are proposed, i.e., in the first era, the ocean is a geographic barrier for mankind; in the second era, the ocean is a road for human transportation; in the third era, the ocean is a granary for mankind; in the fourth era, the ocean is a treasure house of mankind’s natural resources. Viewing from the last three eras, we can know that the ocean plays an important role in promoting the creation, production, and accumulation of human wealth. This paper argues the four-era theory of the relationship between humans and the ocean, also get the following conclusion: every era has the most significant feature of this era. This most significant feature function is the most important, largest, latest, and trendy contribution of the oceans to humans in this era; the four-era theory of the relationship between humans and the ocean also shows the continuous improvement process of human influence and utilization of the oceans; the continuous improvement of human influence and utilization of the ocean is realized by improvement of science and technology; the ability of humans to influence and utilize the oceans in the second era surpassed the first era is due to advances in shipbuilding technology and navigation technology; humans’ ability to influence and utilize the ocean in the third era surpassed the second era due to advances in biotechnology; and the ability of humans to influence and utilize the ocean in the fourth era surpassed the third era due to the advancement and application of all-round science and technology; Historically, once a country has maritime hegemony, this country would become wealthy, powerful, and the leaders of maritime civilization.

Contrasting genetic, acoustic, and morphological differentiation in two closely related gladiator frogs (Hylidae: Boana) across a common Neotropical landscape

Mountain chains and rivers are often found to represent barriers promoting vicariant differentiation in terrestrial vertebrates. Previous studies have supported the idea that the Cordillera de Mérida (CM), the easternmost branch of the Northern Andes, represents a geographic barrier for vertebrates, including frogs. Previous studies have also suggested that the Orinoco River (OR), the biggest river in Venezuela, also represents a geographic barrier for terrestrial vertebrates. Boana pugnax and B. xerophylla are two Neotropical hylids, members of the B. faber species group, that are distributed on either side of the CM, and whose ranges extend up to 605 and 2450 m in elevation, respectively. In addition, B. xerophylla occurs on either side of the OR. Herein, we assess the genetic, acoustic, and morphological differentiation within B. pugnax and within B. xerophylla across the CM and within B. xerophylla across the OR, and test if genetic differentiation is correlated with geographic distance. We also evaluated the acoustic differentiation between the recently recognized B. xerophylla and its sister species, B. crepitans, and found marked differences between advertisement calls, corroborating their status as distinct species. Genetic and morphometric analyses of populations from opposite sides of the CM revealed differentiation in B. pugnax but not in B. xerophylla. Within the latter species, we found molecular, acoustic, and morphometric differentiation among samples of B. xerophylla from western Venezuela versus the Guiana Shield. Genetic variation within B. pugnax and within B. xerophylla was not explained by geographic distance. Thus, our data show conspecific population structure across the CM in B. pugnax, plus the possible existence of two species within what today is considered B. xerophylla, yet the CM apparently is not involved in this divergence. These results suggest that even for closely related species with shared ecology and distribution, genetic and phenotypic differentiation respond differently to common ecological or historical factors.

Paleontological Evidence Against a Major Geographic Barrier at about the Paleolatitude of Colorado, USA, during the Late Campanian (Late Cretaceous): The Conspicuous Absence of Endemic Subclades of Chasmosaurine Ceratopsid (Horned) Dinosaurs and Its Significance

Several paleontologists have suggested that a major geographic barrier at about the paleolatitude of Colorado either prevented or severely restricted biogeographic exchange between the northern and southern regions of western North America during the Late Campanian. However, the origin and nature of this barrier remains enigmatic. In the present study, this hypothesis is tested by determining whether the diversification of Late Campanian chasmosaurine ceratopsid (horned) dinosaurs was affected by the presence of a barrier or, in other words, whether the biogeographic distribution of closely related species was nonrandom with respect to a line of paleolatitude drawn across Colorado. The results of this test indicate that there could not have been a major geographic barrier, which has implications for paleoclimatic and paleogeographic reconstructions of the Colorado region during its early Laramide history.

Health inequity on access to services in the ethnic minority regions of Northeastern Myanmar: a cross-sectional study

ObjectivesTo evaluate health inequity on access to services in the ethnic regions of Northeastern Myanmar from three points of analysis: geographic barrier, gender-based disparity and financial burden of health services.SettingA multistage-stratified random cluster survey was conducted in Shan State Special Region 2 and Eastern Shan State Special Region 4 of Northeastern Myanmar in 2016, including a total number of 774 households.ParticipantsA total number of 4235 participants were recruited during the survey.Primary and secondary outcome measuresGeographic distance, gender, household income and inpatient/outpatient service utilisation.ResultsThe study results showed that residents living within 5 km of any form of healthcare facilities paid more outpatient visits (90.06 visits per thousand population) in the past 2 weeks, compared with those living 5–20 km and over 20 km (54.84 and 54.02 per thousand population, respectively) from healthcare facilities. A similar trend with little significant differences was found for inpatient service use. Regarding household income, adults with an annual household income of above US$720 were more likely to seek outpatient service (OR=1.43, 95% CI 0.98 to 2.10) compared with those with an annual income of <US$360. After adjusting for other covariates, female adults were less likely to seek inpatient treatment (OR=0.55, 95% CI 0.35 to 0.84) and outpatient services (OR=0.86, 95% CI 0.64 to 1.15) than male adults.ConclusionsGeographic barrier, gender-based disparity and financial burdens were identified as key causes that significantly restrict ethnic people’s access to healthcare facilities. The study concludes that tackling health inequity in Northeastern Myanmar ethnic regions requires an improved primary healthcare system, proper financial protection mechanisms and a special focus on women.