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1.
J Zoo Wildl Med ; 52(1): 57-66, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33827161

RESUMO

This retrospective case series describes the clinicopathologic findings, diagnoses, treatment, and outcomes of 10 hand-reared newborn giraffe (Giraffa camelopardalis) calves admitted to a university teaching hospital for intensive care. Ten calves (five males, five females; nine reticulated giraffes [Giraffa camelopardalis reticulata], one Masai giraffe [G. c. tippelskirchi]), were admitted under 2 days of age. Inadequate transfer of passive immunity was suspected in 5 of 10 calves based on assessment of serum total solids and globulin values. These calves were treated with oral frozen bovine colostrum and/or intravenous hyperimmune bovine plasma. Diarrhea occurred in 6 of 10 calves and was managed with supportive care, fecal microbiota transplantation, and limiting milk intake (offering 10% body weight [BW] in milk per day, while feeding <2 L per meal at 2- to 4-hr intervals). Less common diagnoses included pneumonia (n = 3) and mycoplasma-associated septic arthritis (n = 1). Eight calves received systemic antimicrobial therapy. Hyperlactatemia (lactate > 5 mmol/L; n = 8) and hypercreatininemia (creatinine > 2.0 mg/dl, n = 7) were the most common presenting laboratory abnormalities, which resolved with intravenous fluid therapy. All neonatal giraffes survived to discharge after a median hospitalization of 9.5 days (range, 5-37 days) and were successfully hand-reared at their place of birth. In conclusion, neonatal giraffe calves can be intensively managed in a hospital environment. Diarrhea was a common clinical problem and can be related to feeding regimens. Intravenous hyperimmune bovine plasma infusion was well tolerated to manage failure of transfer of passive immunity in calves with inadequate colostrum administration. The current study supports that compromised neonatal giraffe calves may carry an excellent prognosis after early, intensive intervention.


Assuntos
Criação de Animais Domésticos/métodos , Animais Recém-Nascidos , Cuidados Críticos/métodos , Girafas , Animais , Feminino , Hospitais Veterinários , Masculino , Estudos Retrospectivos
3.
Proc Natl Acad Sci U S A ; 117(15): 8410-8415, 2020 04 14.
Artigo em Inglês | MEDLINE | ID: mdl-32229554

RESUMO

Calendar-dated tree-ring sequences offer an unparalleled resource for high-resolution paleoenvironmental reconstruction. Where such records exist for a few limited geographic regions over the last 8,000 to 12,000 years, they have proved invaluable for creating precise and accurate timelines for past human and environmental interactions. To expand such records across new geographic territory or extend data for certain regions further backward in time, new applications must be developed to secure "floating" (not yet absolutely dated) tree-ring sequences, which cannot be assigned single-calendar year dates by standard dendrochronological techniques. This study develops two approaches to this problem for a critical floating tree-ring chronology from the East Mediterranean Bronze-Iron Age. The chronology is more closely fixed in time using annually resolved patterns of 14C, modulated by cosmic radiation, between 1700 and 1480 BC. This placement is then tested using an anticorrelation between calendar-dated tree-ring growth responses to climatically effective volcanism in North American bristlecone pine and the Mediterranean trees. Examination of the newly dated Mediterranean tree-ring sequence between 1630 and 1500 BC using X-ray fluorescence revealed an unusual calcium anomaly around 1560 BC. While requiring further replication and analysis, this anomaly merits exploration as a potential marker for the eruption of Thera.

4.
Compend Contin Educ Dent ; 41(1): 26-30; quiz 31, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31895579

RESUMO

Dental implants arguably have become the preferred treatment modality for replacing missing teeth. The success of implants, however, depends on the precision of the implant placement to effectively support prosthetic restorations. With the evolution of static surgical guides, implant dentistry science has taken enormous strides toward ensuring accurate placement of dental implant fixtures, yet emerging digital protocols show the potential for dynamic real-time clinical support to the operator. Robotic-assisted dental surgery (RADS) is a novel form of dynamic surgical guidance that, in addition to visual navigation, offers haptic guidance for implant treatment planning, osteotomy preparation, and implant placement. This article discusses RADS and includes a case study that, to the authors' knowledge, is the first report of a robotic-assisted dental procedure with quantitative accuracy analysis for prosthetically driven planning and immediate placement of a single-tooth replacement.


Assuntos
Implantes Dentários , Procedimentos Cirúrgicos Robóticos , Cirurgia Assistida por Computador , Implantação Dentária Endóssea , Planejamento de Assistência ao Paciente
5.
Sci Adv ; 4(8): eaar8241, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-30116779

RESUMO

The mid-second millennium BCE eruption of Thera (Santorini) offers a critically important marker horizon to synchronize archaeological chronologies of the Aegean, Egypt, and the Near East and to anchor paleoenvironmental records from ice cores, speleothems, and lake sediments. Precise and accurate dating for the event has been the subject of many decades of research. Using calendar-dated tree rings, we created an annual resolution radiocarbon time series 1700-1500 BCE to validate, improve, or more clearly define the limitations for radiocarbon calibration of materials from key eruption contexts. Results show an offset from the international radiocarbon calibration curve, which indicates a shift in the calibrated age range for Thera toward the 16th century BCE. This finding sheds new light on the long-running debate focused on a discrepancy between radiocarbon (late 17th-early 16th century BCE) and archaeological (mid 16th-early 15th century BCE) dating evidence for Thera.

6.
Philos Trans A Math Phys Eng Sci ; 375(2102)2017 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-28784707

RESUMO

Changes of ocean ventilation rates and deoxygenation are two of the less obvious but important indirect impacts expected as a result of climate change on the oceans. They are expected to occur because of (i) the effects of increased stratification on ocean circulation and hence its ventilation, due to reduced upwelling, deep-water formation and turbulent mixing, (ii) reduced oxygenation through decreased oxygen solubility at higher surface temperature, and (iii) the effects of warming on biological production, respiration and remineralization. The potential socio-economic consequences of reduced oxygen levels on fisheries and ecosystems may be far-reaching and significant. At a Royal Society Discussion Meeting convened to discuss these matters, 12 oral presentations and 23 posters were presented, covering a wide range of the physical, chemical and biological aspects of the issue. Overall, it appears that there are still considerable discrepancies between the observations and model simulations of the relevant processes. Our current understanding of both the causes and consequences of reduced oxygen in the ocean, and our ability to represent them in models are therefore inadequate, and the reasons for this remain unclear. It is too early to say whether or not the socio-economic consequences are likely to be serious. However, the consequences are ecologically, biogeochemically and climatically potentially very significant, and further research on these indirect impacts of climate change via reduced ventilation and oxygenation of the oceans should be accorded a high priority.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.

7.
Philos Trans A Math Phys Eng Sci ; 375(2102)2017 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-28784710

RESUMO

For over 50 years, ocean scientists have oddly represented ocean oxygen consumption rates as a function of depth but not temperature in most biogeochemical models. This unique tradition or tactic inhibits useful discussion of climate change impacts, where specific and fundamental temperature-dependent terms are required. Tracer-based determinations of oxygen consumption rates in the deep sea are nearly universally reported as a function of depth in spite of their well-known microbial basis. In recent work, we have shown that a carefully determined profile of oxygen consumption rates in the Sargasso Sea can be well represented by a classical Arrhenius function with an activation energy of 86.5 kJ mol-1, leading to a Q10 of 3.63. This indicates that for 2°C warming, we will have a 29% increase in ocean oxygen consumption rates, and for 3°C warming, a 47% increase, potentially leading to large-scale ocean hypoxia should a sufficient amount of organic matter be available to microbes. Here, we show that the same principles apply to a worldwide collation of tracer-based oxygen consumption rate data and that some 95% of ocean oxygen consumption is driven by temperature, not depth, and thus will have a strong climate dependence. The Arrhenius/Eyring equations are no simple panacea and they require a non-equilibrium steady state to exist. Where transient events are in progress, this stricture is not obeyed and we show one such possible example.This article is part of the themed issue 'Ocean ventilation and deoxygenation in a warming world'.


Assuntos
Modelos Estatísticos , Temperatura , Mudança Climática , Oceanos e Mares , Oxigênio/metabolismo
8.
Opt Express ; 25(12): 13010-13023, 2017 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-28788840

RESUMO

The significant optical and size benefits of using a curved focal surface for imaging systems have been well studied yet never brought to market for lack of a high-quality, mass-producible, curved image sensor. In this work we demonstrate that commercial silicon CMOS image sensors can be thinned and formed into accurate, highly curved optical surfaces with undiminished functionality. Our key development is a pneumatic forming process that avoids rigid mechanical constraints and suppresses wrinkling instabilities. A combination of forming-mold design, pressure membrane elastic properties, and controlled friction forces enables us to gradually contact the die at the corners and smoothly press the sensor into a spherical shape. Allowing the die to slide into the concave target shape enables a threefold increase in the spherical curvature over prior approaches having mechanical constraints that resist deformation, and create a high-stress, stretch-dominated state. Our process creates a bridge between the high precision and low-cost but planar CMOS process, and ideal non-planar component shapes such as spherical imagers for improved optical systems. We demonstrate these curved sensors in prototype cameras with custom lenses, measuring exceptional resolution of 3220 line-widths per picture height at an aperture of f/1.2 and nearly 100% relative illumination across the field. Though we use a 1/2.3" format image sensor in this report, we also show this process is generally compatible with many state of the art imaging sensor formats. By example, we report photogrammetry test data for an APS-C sized silicon die formed to a 30° subtended spherical angle. These gains in sharpness and relative illumination enable a new generation of ultra-high performance, manufacturable, digital imaging systems for scientific, industrial, and artistic use.

9.
Environ Sci Technol ; 48(16): 9890-7, 2014 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-25051305

RESUMO

The influence of ocean acidification in deep-sea ecosystems is poorly understood but is expected to be large because of the presumed low tolerance of deep-sea taxa to environmental change. We used a newly developed deep-sea free ocean CO2 enrichment (dp-FOCE) system to evaluate the potential consequences of future ocean acidification on the feeding behavior of a deep-sea echinoid, the sea urchin, Strongylocentrotus fragilis. The dp-FOCE system simulated future ocean acidification inside an experimental enclosure where observations of feeding behavior were performed. We measured the average movement (speed) of urchins as well as the time required (foraging time) for S. fragilis to approach its preferred food (giant kelp) in the dp-FOCE chamber (-0.46 pH units) and a control chamber (ambient pH). Measurements were performed during each of 4 trials (days -2, 2, 24, 27 after CO2 injection) during the month-long period when groups of urchins were continuously exposed to low pH or control conditions. Although urchin speed did not vary significantly in relation to pH or time exposed, foraging time was significantly longer for urchins in the low-pH treatment. This first deep-sea FOCE experiment demonstrated the utility of the FOCE system approach and suggests that the chemosensory behavior of a deep-sea urchin may be impaired by ocean acidification.


Assuntos
Ácidos/química , Dióxido de Carbono/análise , Comportamento Alimentar , Oceanos e Mares , Ouriços-do-Mar/fisiologia , Análise de Variância , Animais , Concentração de Íons de Hidrogênio , Movimento , Fatores de Tempo
10.
Sci Rep ; 2: 413, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22639723

RESUMO

Ocean acidification poses multiple challenges for coral reefs on molecular to ecological scales, yet previous experimental studies of the impact of projected CO2 concentrations have mostly been done in aquarium systems with corals removed from their natural ecosystem and placed under artificial light and seawater conditions. The Coral-Proto Free Ocean Carbon Enrichment System (CP-FOCE) uses a network of sensors to monitor conditions within each flume and maintain experimental pH as an offset from environmental pH using feedback control on the injection of low pH seawater. Carbonate chemistry conditions maintained in the -0.06 and -0.22 pH offset treatments were significantly different than environmental conditions. The results from this short-term experiment suggest that the CP-FOCE is an important new experimental system to study in situ impacts of ocean acidification on coral reef ecosystems.


Assuntos
Antozoários/metabolismo , Dióxido de Carbono/metabolismo , Recifes de Corais , Ecologia/métodos , Animais , Antozoários/crescimento & desenvolvimento , Carbonato de Cálcio/análise , Geografia , Sedimentos Geológicos/química , Concentração de Íons de Hidrogênio , Ilhas , Biologia Marinha/métodos , Rodófitas/crescimento & desenvolvimento , Rodófitas/metabolismo , Água do Mar/química , Fatores de Tempo , Difração de Raios X
11.
Appl Spectrosc ; 66(3): 237-49, 2012 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22449300

RESUMO

We review the rapid progress made in the applications of Raman spectroscopy to deep-ocean science. This is made possible by deployment of instrumentation on remotely operated vehicles used for providing power and data flow and for precise positioning on targets of interest. Early prototype systems have now been replaced by compact and robust units that have been deployed well over 100 times on an expeditionary basis over a very wide range of ocean depths without failure. Real-time access to the spectra obtained in the vehicle control room allows for expedition decision making. Quantification of some of the solutes in seawater or pore waters observed in the spectra is made possible by self-referencing to the ubiquitous ν(2) water bending peak. The applications include detection of the structure and composition of complex thermogenic gas hydrates both occurring naturally on the sea floor and in controlled sea floor experiments designed to simulate the growth of such natural systems. New developments in the ability to probe the chemistry of sediment pore waters in situ, long thought impossible candidates for Raman study due to fluorescence observed in recovered samples, have occurred. This permits accurate measurement of the abundance of dissolved methane and sulfide in sediment pore waters. In areas where a high gas flux is observed coming out of the sediments a difference of about ×30 between in situ Raman measurement and the quantity observed in recovered cores has been found. New applications under development include the ability to address deep-sea biological processes and the ability to survey the sea floor chemical conditions associated with potential sub-sea geologic CO(2) disposal in abandoned oil and gas fields.

14.
Environ Sci Technol ; 43(3): 610-5, 2009 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19244991

RESUMO

The long-term fate of chemical weapon debris disposed of in the ocean some 50 years ago, now sinking into marine sediments and leaking into the ocean environment, is poorly known. Direct evidence exists showing chemical weapon agents actively being released on the sea floor with detrimental effects including harm to marine life. Thus there is strong interest in determining the fate and lifetime of these materials, their decomposition products, and the affected zones around these sites. Here we study the geochemical properties of a mustard gas breakdown product, 1,4-thioxane (TO), using Raman spectroscopy. We show that TO forms a hydrate with a help-gas (a second guest added to stabilize the hydrate), such as methane or hydrogen sulfide, with the hydrate stability regime some 10 degrees C above pure methane hydrate. The temperature, pressure, and reducing conditions required for hydrate formation commonly occur at known disposal sites. The TO solubility was measured in seawater and found to vary from 0.65 to 0.63 mol/kg water between 4.5 and 25.0 degrees C. Similar to other hydrate systems, the TO solubility decreased in the presence of hydrate. A low solubility in water coupled with its ability to form a hydrate within marine sediments can greatly decrease molecular mobility and increase its lifetime. These results demonstrate how unanticipated reactions with marine sediments can occur, and how little is known of the processes controlling the environmental science of these materials.


Assuntos
Guerra Química , Compostos Heterocíclicos com 1 Anel/análise , Água do Mar/química , Poluentes Químicos da Água/análise , Solubilidade , Análise Espectral Raman
15.
Ann Rev Mar Sci ; 1: 303-27, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-21141039

RESUMO

Scientific knowledge of natural clathrate hydrates has grown enormously over the past decade, with spectacular new findings of large exposures of complex hydrates on the sea floor, the development of new tools for examining the solid phase in situ, significant progress in modeling natural hydrate systems, and the discovery of exotic hydrates associated with sea floor venting of liquid CO2. Major unresolved questions remain about the role of hydrates in response to climate change today, and correlations between the hydrate reservoir of Earth and the stable isotopic evidence of massive hydrate dissociation in the geologic past. The examination of hydrates as a possible energy resource is proceeding apace for the subpermafrost accumulations in the Arctic, but serious questions remain about the viability of marine hydrates as an economic resource. New and energetic explorations by nations such as India and China are quickly uncovering large hydrate findings on their continental shelves.


Assuntos
Gases/análise , Modelos Teóricos , Animais , Mudança Climática , Meio Ambiente , Gases/química , Oceanos e Mares , Termodinâmica
17.
PLoS One ; 2(11): e1124, 2007 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-17987112

RESUMO

There is a concerted global effort to digitize biodiversity occurrence data from herbarium and museum collections that together offer an unparalleled archive of life on Earth over the past few centuries. The Global Biodiversity Information Facility provides the largest single gateway to these data. Since 2004 it has provided a single point of access to specimen data from databases of biological surveys and collections. Biologists now have rapid access to more than 120 million observations, for use in many biological analyses. We investigate the quality and coverage of data digitally available, from the perspective of a biologist seeking distribution data for spatial analysis on a global scale. We present an example of automatic verification of geographic data using distributions from the International Legume Database and Information Service to test empirically, issues of geographic coverage and accuracy. There are over 1/2 million records covering 31% of all Legume species, and 84% of these records pass geographic validation. These data are not yet a global biodiversity resource for all species, or all countries. A user will encounter many biases and gaps in these data which should be understood before data are used or analyzed. The data are notably deficient in many of the world's biodiversity hotspots. The deficiencies in data coverage can be resolved by an increased application of resources to digitize and publish data throughout these most diverse regions. But in the push to provide ever more data online, we should not forget that consistent data quality is of paramount importance if the data are to be useful in capturing a meaningful picture of life on Earth.


Assuntos
Serviços de Informação , Internacionalidade , Especificidade da Espécie , Geografia
18.
Proc Natl Acad Sci U S A ; 104(24): 9915-6, 2007 Jun 12.
Artigo em Inglês | MEDLINE | ID: mdl-17551005

Assuntos
Clima , Efeito Estufa , Humanos
20.
Environ Sci Technol ; 39(18): 7287-93, 2005 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-16201660

RESUMO

We have carried out the second phase of field studies to determine the effectiveness of a coflow injector which mixes liquid CO2 and ambient seawater to produce a hydrate slurry as a possible CO2 delivery method for ocean carbon sequestration. The experiments were carried out at ocean depths of 1000-1300 m in Monterey Bay, CA, using a larger injector than that initially employed under remotely operated vehicle control and imaging of the product. Solidlike composite particles comprised of water, solid CO2 hydrate, and liquid CO2 were produced in both studies. In the recent injections, the particles consistently sank at rates of approximately 5 cm s(-1). The density of the sinking particles suggested that approximately 40% of the injected CO2 was converted to hydrate, while image analysis of the particle shrinking rate indicated a CO2 dissolution rate of 0.76-1.29 micromol cm(-2) s(-1). Plume modeling of the hydrate composite particles suggests that while discrete particles may sink 10-70 m, injections with CO2 mass fluxes of 1-1000 kg s(-1) would result in sinking plumes 120-1000 m belowthe injection point.


Assuntos
Dióxido de Carbono/análise , Carbono/química , Monitoramento Ambiental/métodos , Água do Mar/química , Carbono/análise , Dióxido de Carbono/química , Concentração de Íons de Hidrogênio , Processamento de Imagem Assistida por Computador , Modelos Teóricos , Nitrogênio/análise , Solubilidade , Fatores de Tempo
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