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1.
Proc Natl Acad Sci U S A ; 120(42): e2303964120, 2023 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-37812707

RESUMO

We present stable hydrogen-isotope analyses of volcanic glass ([Formula: see text]Dg) and radiometric ages (U-Pb zircon, U-Th calcite, AMS14C) from deformed sedimentary deposits in the vicinity of the intermontane Pocitos Basin in the central Puna of the Andean Plateau at about 24.5°S. Our results demonstrate 2-km surface uplift since the middle to late Miocene and protracted shortening that persists until the present day, while other sectors of the Puna show evidence for tectonically neutral and/or extensional settings. These findings are at odds with previous studies suggesting near-modern elevations (4 km) of the Puna Plateau since the late Eocene and formation of the intermontane Miocene Arizaro-Pocitos Basin associated with gravitational foundering of a dense lithosphere. Geophysical and geochemical data support the removal of continental lithosphere beneath the Puna, but the timing and mechanisms by which this removal occurs have remained controversial. We hypothesize that intermontane basin formation in the central Puna is the result of crustal shortening since about 20 Ma, followed by rapid surface uplift, likely related to lithospheric delamination.

2.
PeerJ ; 11: e15812, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37671364

RESUMO

Captive breeding programs are an important pillar in biodiversity conservation, aiming to prevent the extinction of threatened species. However, the establishment of self-sustaining populations in the wild through the release of captive-bred animals is often hampered by a high mortality upon release. In this study, we investigated how a 2-week confinement period within a large field enclosure affected the anti-predator behaviour of 'naive' captive-bred hamsters and how potential modifications persisted over time. During three consecutive tests, hamsters were confronted with a moving predator model (a red fox mount, Vulpes vulpes) and their behaviour was filmed. After the initial round of confrontation with the predator model, one group of hamsters (field group) was released into a field enclosure protected from predators, while the other group (control) remained in their individual laboratory cages. After 2 weeks, hamsters from the field group were recaptured and individuals of both groups underwent a second confrontation test. A total of 1 month after their return from the field enclosure, field hamsters were subjected to a last confrontation test. Video analysis, investigating four behavioural variables, revealed that field hamsters significantly modified their behavioural response following the 2 weeks confinement in the enclosure, while this was not the case for control hamsters. In addition, most behavioural modifications in field hamsters persisted over 1 month, while others started to revert. We suggest that an appropriate pre-release period inside a field enclosure will enable naive (captive-bred) hamsters to develop an adequate anti-predator behaviour that will increase their immediate survival probability upon release into the wild. We believe that such measure will be of great importance for hamster conservation programs.


Assuntos
Comportamento Animal , Conservação dos Recursos Naturais , Cricetinae , Reação de Fuga , Abrigo para Animais , Reforço Psicológico , Animais , Raposas , Comportamento Animal/fisiologia , Reação de Fuga/fisiologia , Conservação dos Recursos Naturais/métodos
3.
Zootaxa ; 5162(1): 1-36, 2022 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-36095526

RESUMO

The Rohrthripidae is a family of fossil tubuliferan thrips known exclusively from the Cretaceous. Despite typical tubuliferan features, these thrips show terebrantian character states, particularly on the wings and antennae, which have been interpreted as plesiomorphic. At present, the family includes only a single genus, with seven species. In the present study, 11 new species and four new genera of these ancestral thrips are described from Burmese Cenomanian amber: Adstrictubothrips mirapterus gen. et sp. n., Gemineurothrips microcephalus gen. et sp. n., Gemineurothrips peculiaris gen. et sp. n., Paralleloalathrips bivenatus gen. et sp. n., Rohrthrips brachyvenis sp. n., Rohrthrips multihamuli sp. n., Rohrthrips pandemicus sp. n., Rohrthrips rhamphorhynchus sp. n., Rohrthrips setiger sp. n., Sesquithrips markpankowskii gen. et sp. n. and Sesquithrips rostratus gen. et sp. n. Furthermore, Alavathrips moralesi, a species from Spanish Cretaceous amber, is placed into the Rohrthripidae and its sex is reinterpreted as male. The present study, moreover, provides a tighter definition of the Rohrthripidae and a more detailed description of important character states. Finally, it is outlined why it makes taxonomic sense to distinguish Rohrthripidae from the modern Tubulifera, the Phlaeothripidae.


Assuntos
Âmbar , Tisanópteros , Animais , Fósseis , Masculino , Asas de Animais
4.
Polymers (Basel) ; 14(16)2022 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-36015670

RESUMO

The article is the first review encompassing the study and the applications of polyester-based coatings for the corrosion protection of steel. The impact of corrosion and the challenges encountered thus far and the solutions encountered in industry are addressed. Then, the use of polyesters as a promising alternative to current methods, such as phosphating, chromating, galvanization, and inhibitors, are highlighted. The classifications of polyesters and the network structure determine the overall applications and performance of the polymer. The review provides new trends in green chemistry and smart and bio-based polyester-based coatings. Finally, the different applications of polyesters are covered; specifically, the use of polyesters in surface coatings and for other industrial uses is discussed.

5.
J Neurochem ; 163(1): 53-67, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36000528

RESUMO

Cholesterol levels have been repeatedly linked to Alzheimer's Disease (AD), suggesting that high levels could be detrimental, but this effect is likely attributed to Low-Density Lipoprotein (LDL) cholesterol. On the other hand, High-Density Lipoproteins (HDL) cholesterol levels have been associated with reduced brain amyloidosis and improved cognitive function. However, recent findings have suggested that HDL-functionality, which depends upon the HDL-cargo proteins associated with HDL, rather than HDL levels, appears to be the key factor, suggesting a quality over quantity status. In this report, we have assessed the HDL-cargo (Cholesterol, ApoA-I, ApoA-II, ApoC-I, ApoC-III, ApoD, ApoE, ApoH, ApoJ, CRP, and SAA) in stable healthy control (HC), healthy controls who will convert to MCI/AD (HC-Conv) and AD patients (AD). Compared to HC we observed an increased cholesterol/ApoA-I ratio in AD and HC-Conv, as well as an increased ApoD/ApoA-I ratio and a decreased ApoA-II/ApoA-I ratio in AD. Higher cholesterol/ApoA-I ratio was also associated with lower cortical grey matter volume and higher ventricular volume, while higher ApoA-II/ApoA-I and ApoJ/ApoA-I ratios were associated with greater cortical grey matter volume (and for ApoA-II also with greater hippocampal volume) and smaller ventricular volume. Additionally, in a clinical status-independent manner, the ApoE/ApoA-I ratio was significantly lower in APOE ε4 carriers and lowest in APOE ε4 homozygous. Together, these data indicate that in AD patients the composition of HDL is altered, which may affect HDL functionality, and such changes are associated with altered regional brain volumetric data.


Assuntos
Doença de Alzheimer , Lipoproteínas HDL , Apolipoproteína A-I/metabolismo , Apolipoproteína A-II/metabolismo , Apolipoproteína C-III/metabolismo , Apolipoproteína E4/metabolismo , Apolipoproteínas E/metabolismo , Encéfalo/metabolismo , Colesterol/metabolismo , Humanos , Lipoproteínas HDL/metabolismo , Lipoproteínas LDL/metabolismo
6.
Proc Natl Acad Sci U S A ; 119(28): e2121388119, 2022 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-35759654

RESUMO

East Africa is a global biodiversity hotspot and exhibits distinct longitudinal diversity gradients from west to east in freshwater fishes and forest mammals. The assembly of this exceptional biodiversity and the drivers behind diversity gradients remain poorly understood, with diversification often studied at local scales and less attention paid to biotic exchange between Afrotropical regions. Here, we reconstruct a river system that existed for several millennia along the now semiarid Kenya Rift Valley during the humid early Holocene and show how this river system influenced postglacial dispersal of fishes and mammals due to its dual role as a dispersal corridor and barrier. Using geomorphological, geochronological, isotopic, and fossil analyses and a synthesis of radiocarbon dates, we find that the overflow of Kenyan rift lakes between 12 and 8 ka before present formed a bidirectional river system consisting of a "Northern River" connected to the Nile Basin and a "Southern River," a closed basin. The drainage divide between these rivers represented the only viable terrestrial dispersal corridor across the rift. The degree and duration of past hydrological connectivity between adjacent river basins determined spatial diversity gradients for East African fishes. Our reconstruction explains the isolated distribution of Nilotic fish species in modern Kenyan rift lakes, Guineo-Congolian mammal species in forests east of the Kenya Rift, and recent incipient vertebrate speciation and local endemism in this region. Climate-driven rearrangements of drainage networks unrelated to tectonic activity contributed significantly to the assembly of species diversity and modern faunas in the East African biodiversity hotspot.


Assuntos
Biodiversidade , Rios , Animais , Peixes , Fósseis , Quênia , Lagos , Mamíferos
7.
J Exp Biol ; 224(12)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34132335

RESUMO

The period of emancipation in seabirds, when juveniles change from a terrestrial existence to a life at sea, is associated with many challenges. Apart from finding favourable foraging sites, they have to develop effective prey search patterns and physiological capacities that enable them to capture sufficient prey to meet their energetic needs. Animals that dive to forage, such as king penguins (Aptenodytes patagonicus), need to acquire an adequate breath-hold capacity, allowing them to locate and capture prey at depth. To investigate the ontogeny of their dive capacity and foraging performance, we implanted juvenile king penguins before their first departure to sea and also adult breeders with a data-logger recording pressure and temperature. We found that juvenile king penguins possess a remarkable dive capacity when leaving their natal colony, enabling them to conduct dives in excess of 100 m within their first week at sea. Despite this, juvenile dive/foraging performance, investigated in relation to dive depth, remained below the adult level throughout their first year at sea, probably reflecting physiological limitations as a result of incomplete maturation. A significantly shallower foraging depth of juveniles, particularly during their first 5 months at sea, could also indicate differences in foraging strategy and targeted prey. The initially greater wiggle rate suggests that juveniles fed opportunistically and also targeted different prey from adults and/or that many of the wiggles of juveniles reflect unsuccessful prey-capture attempts, indicating a lower foraging proficiency. After 5 months, this difference disappeared, suggesting sufficient physical maturation and improvement of juvenile foraging skills.


Assuntos
Mergulho , Spheniscidae , Animais , Comportamento Animal , Comportamento Alimentar , Temperatura
8.
Sci Rep ; 11(1): 5970, 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727574

RESUMO

In active tectonic settings dominated by strike-slip kinematics, slip partitioning across subparallel faults is a common feature; therefore, assessing the degree of partitioning and strain localization is paramount for seismic hazard assessments. Here, we estimate a slip rate of 18.8 ± 2.0 mm/year over the past 9.0 ± 0.1 ka for a single strand of the Liquiñe-Ofqui Fault System, which straddles the Main Cordillera in Southern Chile. This Holocene rate accounts for ~ 82% of the trench-parallel component of oblique plate convergence and is similar to million-year estimates integrated over the entire fault system. Our results imply that strain localizes on a single fault at millennial time scale but over longer time scales strain localization is not sustained. The fast millennial slip rate in the absence of historical Mw > 6.5 earthquakes along the Liquiñe-Ofqui Fault System implies either a component of aseismic slip or Mw ~ 7 earthquakes involving multi-trace ruptures and > 150-year repeat times. Our results have implications for the understanding of strike-slip fault system dynamics within volcanic arcs and seismic hazard assessments.

9.
Graefes Arch Clin Exp Ophthalmol ; 259(6): 1643-1649, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33464378

RESUMO

PURPOSE: To evaluate the influence of the type of the keratectasia and preoperative keratometry readings on the efficacy of implantation of iris-fixated phakic anterior chamber intraocular lenses (pIOL) in patients with keratoconus. METHODS: In this retrospective study, iris-fixated pIOLs (Artisan/Artiflex (Ophtec®), Verisyse/Veriflex (AMO®)) were implanted in 38 eyes of 22 patients with stable keratoconus. Thirty-six eyes underwent corneal crosslinking (CXL) prior to the lens implantation. The refractive outcome was evaluated 6 weeks postoperatively and the influence of preoperative refraction and topo- and tomographical factors were analyzed. RESULTS: The mean postoperative uncorrected distance visual acuity (UDVApost) was 0.25 ± 0.15 logMAR and was not statistically different from the mean preoperative corrected distance visual acuity (CDVApre), which was 0.24 ± 0.13 logMAR. Twenty-seven eyes (71%) reached UDVApost/CDVApre ≥ 1 (efficacy index), whereas patients with PMD-like ectasia (n = 14) showed significantly (p = 0.003) higher efficacy index (100%) than patients diagnosed with keratoconus (n = 24) (54%). Higher eccentricity of the maximum posterior elevation showed a significant beneficial influence on the efficacy index (p = 0.021). Furthermore, a higher Amsler-Krumeich stage and preoperative MAE were correlated with a worse UDVApost. The mean absolute spherical equivalent was significantly decreased from 5.71 ± 4.96 D to 1.25 ± 1.20 D (p < 0.001). No significant difference was found in endothelial cell count. CONCLUSION: The results indicate that the implantation of phakic iris-fixated anterior chamber IOLs is a reasonable refractive option for patients with keratoconus. Keratoconus patients with a pellucidal marginal degeneration (PMD)-like appearance ectasia seem to benefit most from such procedures.


Assuntos
Ceratocone , Lentes Intraoculares Fácicas , Câmara Anterior/diagnóstico por imagem , Câmara Anterior/cirurgia , Humanos , Ceratocone/diagnóstico , Ceratocone/cirurgia , Implante de Lente Intraocular , Refração Ocular , Estudos Retrospectivos , Resultado do Tratamento
10.
Zootaxa ; 4858(1): zootaxa.4858.1.7, 2020 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-33056245

RESUMO

Thermothrips mohelensis Pelikán is an extremely rare thrips found in dry steppe grassland ecosystems (Pelikán 1949, 1995; Ulitzka 2019a). It has been reported from only a few locations and almost always in very low abundance: one female each has been collected in Germany (Ulitzka 2019a), Slovenia (Kucharczyk 2008) and Turkey (Tunç 1992), two females are known from Iran (Mirab-balou Chen 2013), three from Poland (Zawirska 1988; Kucharczyk 2007) and six from Western Russia (Schliephake 1977). Larger series including males and larvae are known only from Czechoslovakia (Pelikán 1949, 1995) and from Yakutia, East Siberia where-besides other specimens-the larvae discussed below have been collected (see Evdokarova Kucharczyk 2020). The fragmented and selective occurrence of this species in steppe habitats has been interpreted to represent scattered relict populations that may have remained from a more extensive distribution far back, possibly in the wide dry grasslands of the Late Pleistocene (Ulitzka 2019a). Similar to other specialist species of those barren habitats T. mohelensis is severely threatened by the general decline of these fragile ecosystems due to natural succession or anthropogenic impact (Kucharczyk 2008; Kucharczyk Kucharcyk 2008; Ulitzka 2019a). T. mohelensis is a thermophilous (zur Strassen 2003) and highly xerophilous species. This thrips was erroneously considered an hydrophilous wetland thrips (Bhatti 1998) due to a mistranslation (see Ulitzka 2019a). T. mohelensis lives and breeds monophagously in flowers of Galium (Rubiaceae), particularly G. verum but also G. mollugo (Pelikán 1949, 1995; Schliephake 1972; Tunç 1992).


Assuntos
Tisanópteros , Animais , Ecossistema , Feminino , Larva , Masculino
11.
Zootaxa ; 4786(2): zootaxa.4786.2.10, 2020 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-33056490

RESUMO

Amber has rarely been found in Africa and only a few samples with fossil inclusions are known (Kiefert et al. 2015). The most important fossiliferous find was reported from an outcrop at the north-western Plateau of Ethiopia a decade ago, revealing diverse inclusions of arthropods, plant remains, fungi and microorganisms (Schmidt et al. 2010). Initially, this amber was classified as originating from the mid-Cretaceous. Later studies, however, have raised questions about this determination and indicated a much younger age: Cenozoic, likely Miocene (Coty et al. 2016, Perrichot et al. 2016, Perrichot et al. 2018). The contradictory-and rather controversial discussed-new dating was based on spectroscopic analyses, revised palynological data and more comprehensive palaeoentomological results showing that insect fossils mostly belong to extant families and genera. In total, Schmidt et al. (2010) reported 22 insects from eight identified orders including two specimens of Thysanoptera: "an undetermined, wingless thrips" (obviously a larva) and a female associated with Merothripidae. A more detailed analysis of these specimens is the objective of the present study; regarding the larva, only a rough classification and description is given, as fossil larvae cannot be definitely associated with adult specimens.


Assuntos
Âmbar , Tisanópteros , Animais , Feminino , Fósseis , Insetos
12.
J Alzheimers Dis ; 77(2): 733-744, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32741823

RESUMO

BACKGROUND: The link between cholesterol and Alzheimer's disease (AD) has received much attention, as evidence suggests high levels of cholesterol might be an AD risk factor. The carriage of cholesterol and lipids through the body is mediated via lipoproteins, some of which, particularly apolipoprotein E (ApoE), are intimately linked with AD. In humans, high density lipoprotein (HDL) is regarded as a "good" lipid complex due to its ability to enable clearance of excess cholesterol via 'cholesterol reverse transport', although its activities in the pathogenesis of AD are poorly understood. There are several subclasses of HDL; these range from the newly formed small HDL, to much larger HDL. OBJECTIVE: We examined the major subclasses of HDL in healthy controls, mild cognitively impaired, and AD patients who were not taking statins to determine whether there were HDL profile differences between the groups, and whether HDL subclass levels correlated with plasma amyloid-ß (Aß) levels or brain Aß deposition. METHODS: Samples from AIBL cohort were used in this study. HDL subclass levels were assessed by Lipoprint while Aß1-42 levels were assessed by ELISA. Brain Aß deposition was assessed by PET scan. Statistical analysis was performed using parametric and non-parametric tests. RESULTS: We found that small HDL subclass is reduced in AD patients and it correlates with cognitive performance while plasma Aß concentrations do not correlate with lipid profile or HDL subfraction levels. CONCLUSION: Our data indicate that AD patients exhibit altered plasma HDL profile and that HDL subclasses correlate with cognitive performances.


Assuntos
Doença de Alzheimer/sangue , Doença de Alzheimer/psicologia , Peptídeos beta-Amiloides/sangue , Cognição/fisiologia , Lipoproteínas HDL/sangue , Fragmentos de Peptídeos/sangue , Desempenho Psicomotor/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/genética , Peptídeos beta-Amiloides/genética , Biomarcadores/sangue , Estudos de Coortes , Feminino , Humanos , Lipoproteínas HDL/genética , Masculino , Fragmentos de Peptídeos/genética
13.
Nat Commun ; 11(1): 2881, 2020 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-32513970

RESUMO

The Victoria microplate between the Eastern and Western Branches of the East African Rift System is one of the largest continental microplates on Earth. In striking contrast to its neighboring plates, Victoria rotates counterclockwise with respect to Nubia. The underlying cause of this distinctive rotation has remained elusive so far. Using 3D numerical models, we investigate the role of pre-existing lithospheric heterogeneities in continental microplate rotation. We find that Victoria's rotation is primarily controlled by the distribution of rheologically stronger zones that transmit the drag of the major plates to the microplate and of the mechanically weaker mobile belts surrounding Victoria that facilitate rotation. Our models reproduce Victoria's GPS-derived counterclockwise rotation as well as key complexities of the regional tectonic stress field. These results reconcile competing ideas on the opening of the rift system by highlighting differences in orientation of the far-field divergence, local extension, and the minimum horizontal stress.

14.
Zootaxa ; 4585(1): zootaxa.4585.1.2, 2019 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-31716180

RESUMO

Rohrthripidae is a family of fossil thrips in the thysanopteran suborder Tubulifera. It includes a single genus, Rohrthrips, of which two species are previously known. Despite typical tubuliferan features, these thrips also show some terebrantian character states, particularly in the wings and antennae, and these are here interpreted as plesiomorphic. Five new species of these ancestral thrips are described from Burmese Cenomanian amber: Rohrthrips breviceps sp. n., Rohrthrips jiewenae sp. n., Rohrthrips maryae sp. n., Rohrthrips patrickmuelleri sp. n. and Rohrthrips schizovenatus sp. n.. Structures on the wings support the conclusion that the wings of Tubulifera are homologous with those of Terebrantia. Syninclusions in the amber fragments provide evidence of the diet and habitats of these ancestral thrips.


Assuntos
Âmbar , Tisanópteros , Animais , Ecossistema , Fósseis , Asas de Animais
15.
Zootaxa ; 4657(3): zootaxa.4657.3.12, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31716779

RESUMO

Concerning the description of Rohrthrips patrickmuelleri Ulitzka (2019), it has been brought to my attention that the depositary and serial number of the holotype was not given. This information is given below in order to comply with ICZN, Article 16.4.2 (1999).


Assuntos
Âmbar , Tisanópteros , Animais , Fósseis , Asas de Animais
16.
Zootaxa ; 4686(1): zootaxa.4686.1.9, 2019 Oct 14.
Artigo em Inglês | MEDLINE | ID: mdl-31719505

RESUMO

The thysanopteran genus Chiridurothrips Okajima is known from a single extant species, C. hisakoae Okajima, collected in Japan (ThripsWiki 2019). Occurring on dead leaves and branches of evergreen trees in the subtropical Ryukyu Islands, this species remains known from only five females (Okajima 1981, 2006; also pers. comm. 2018). Within Phlaeothripidae, Chiridurothrips is associated with the tribe Plectrothripini. Species of this sub-group feed on fungal hyphae or the break-down products of fungal attack on decaying plant material (Mound Ng 2018). They are found mainly under the bark of trees or on dead branches, and they do not seem to inhabit leaf-litter (Okajima 1981). At present, Plectrothripini comprises 60 extant species in 13 genera, with no fossils recorded. Of these species 32 are placed in the genus Plectrothrips Hood, ten in Streptothrips Priesner, and six in Chirothripoides Bagnall, whereas both Menothrips Hood and Mastigothrips Priesner each include only two species. The remaining eight species are all placed in separate monobasic genera (ThripsWiki 2019). Concerning this strongly asymmetric classification, Mound and Ng (2018) suggest that Plectrothripini might be particularly old, with the large number of monobasic genera each representing a relict lineage. An alternative possibility, however, might be an unusual instability in the genes controlling morphogenetic processes, and thus resulting in striking autapomorphies on which each one of these genera is diagnosed (Mound Ng 2018). Species associated with Plectrothripini share the following character states (Okajima 1981; Mound Tree 2017): antennae 8-segmented, segment II with the campaniform sensillum situated in the basal half, III-IV with stout sense cones, VIII slender with narrow base; head with posterior ocelli close to compound eyes; pronotum commonly with sclerotized plate eroded or reduced, prosternal basantra week or absent; legs with fore tarsal tooth large; mid and hind tibiae commonly with apical spur-like setae; macropterae with fore wings parallel-sided, usually with duplicated cilia; pelta broad at base, abdominal tergite II eroded laterally; abdominal sternites often with reticulate glandular areas. Regarding the fore wings, it seems worth mentioning that in some members of Plectrothripini the subbasal wing vein is reduced and thus the three subbasal wing setae are lacking (see Plectrothrips tenuis Okajima, Chiridurothrips [c.f. fig. 2], Chirothripoides, Lonchothrips Hood; Bhatti 1998; Okajima 1981). This short vein that is present in (almost all) other macropterous Phlaeothripidae has been interpreted as a plesiomorphic feature that resulted from the reduction of a former well-developed longitudinal first vein of ancestral Tubulifera, the Rohrthripidae (Ulitzka 2018, 2019).


Assuntos
Âmbar , Tisanópteros , Animais , República Dominicana , Feminino , Fósseis , Japão
17.
J Exp Biol ; 222(Pt 20)2019 10 17.
Artigo em Inglês | MEDLINE | ID: mdl-31624105

RESUMO

Like all birds, penguins undergo periodic molt, during which they replace old feathers. However, unlike other birds, penguins replace their entire plumage within a short period while fasting ashore. During molt, king penguins (Aptenodytes patagonicus) lose half of their initial body mass, most importantly their insulating subcutaneous fat and half of their pectoral muscle mass. The latter might challenge their capacity to generate and sustain a sufficient mechanical power output to swim to distant food sources and propel themselves to great depth for successful prey capture. To investigate the effects of the annual molt fast on their dive/foraging performance, we studied various dive/foraging parameters and peripheral temperature patterns in immature king penguins across two molt cycles, after birds had spent their first and second year at sea, using implanted data-loggers. We found that the dive/foraging performance of immature king penguins was significantly reduced during post-molt foraging trips. Dive and bottom duration for a given depth were shorter during post-molt and post-dive surface interval duration was longer, reducing overall dive efficiency and underwater foraging time. We attribute this decline to the severe physiological changes that birds undergo during their annual molt. Peripheral temperature patterns differed greatly between pre- and post-molt trips, indicating the loss of the insulating subcutaneous fat layer during molt. Peripheral perfusion, as inferred from peripheral temperature, was restricted to short periods at night during pre-molt but occurred throughout extended periods during post-molt, reflecting the need to rapidly deposit an insulating fat layer during the latter period.


Assuntos
Mergulho/fisiologia , Muda/fisiologia , Spheniscidae/fisiologia , Animais , Plumas/crescimento & desenvolvimento , Comportamento Alimentar/fisiologia , Feminino , Masculino , Oceanos e Mares , Temperatura
18.
Integr Zool ; 14(1): 48-64, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30251470

RESUMO

Bio-loggers are miniaturized autonomous devices that record quantitative data on the state of free-ranging animals (e.g. behavior, position and physiology) and their natural environment. This is especially relevant for species where direct visual observation is difficult or impossible. Today, ongoing technical development allows the monitoring of numerous parameters in an increasing range of species over extended periods. However, the external attachment of devices might affect various aspects of animal performance (energetics, thermoregulation, foraging as well as social and reproductive behavior), which ultimately affect fitness. External attachment might also increase entanglement risk and the conspicuousness of animals, leaving them more vulnerable to predation. By contrast, implantation of devices can mitigate many of these undesirable effects and might be preferable, especially for long-term studies, provided that the many challenges associated with surgical procedures can be mastered. Implantation may then allow us to gather data that would be impossible to obtain otherwise and thereby may provide new and ecologically relevant insights into the life of wild animals. Here, we: (i) discuss the pros and cons of attachment methods; (ii) highlight recent field studies that used implanted bio-loggers to address eco-physiological questions in a wide range of species; and (iii) discuss logger implantation in light of ethical considerations.


Assuntos
Animais Selvagens , Comportamento Animal/fisiologia , Monitorização Fisiológica/veterinária , Animais , Meio Ambiente , Monitorização Fisiológica/instrumentação , Atividade Motora
19.
Zootaxa ; 4486(4): 548-558, 2018 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-30313740

RESUMO

Burmite, a Cretaceous amber coming from the north of Myanmar, is known to preserve a great diversity of fossil arthropods, particularly insects. Many inclusions of different taxa in several insect orders have been well analysed, but this is the first study focussed on the Thysanoptera found in Burmite. In the sub-order Terebrantia, family Merothripidae, Myanmarothrips pankowskiorum gen. n., sp. n. is recognized in various amber samples from a total of 34 females but only one male. In the sub-order Tubulifera, Rohrthrips burmiticus sp. n. is based on a single female with a tubular tenth abdominal segment. This is an exceptionally well-preserved specimen, and details of the mouth parts indicate that the gnathal apparatus of modern Tubulifera was already developed in the Cretaceous. Due to plesiomorphic characters with respect to extant Tubulifera, the genus Rohrthrips is transferred to Rohrthripidae fam. n., and this family is clearly differentiated from extant Phlaeothripidae.


Assuntos
Âmbar , Tisanópteros , Animais , Feminino , Fósseis , Insetos , Masculino , Mianmar
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