Comparative phylogeography of the ocean planet Bowen, Brian W.; Gaither, Michelle R.; DiBattista, Joseph D. ...
Proceedings of the National Academy of Sciences - PNAS,
07/2016, Letnik:
113, Številka:
29
Journal Article
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Understanding how geography, oceanography, and climate have ultimately shaped marine biodiversity requires aligning the distributions of genetic diversity across multiple taxa. Here, we examine ...phylogeographic partitions in the sea against a backdrop of biogeographic provinces defined by taxonomy, endemism, and species composition. The taxonomic identities used to define biogeographic provinces are routinely accompanied by diagnostic genetic differences between sister species, indicating interspecific concordance between biogeography and phylogeography. In cases where individual species are distributed across two or more biogeographic provinces, shifts in genotype frequencies often align with biogeographic boundaries, providing intraspecific concordance between biogeography and phylogeography. Here, we provide examples of comparative phylogeography from (i) tropical seas that host the highest marine biodiversity, (ii) temperate seas with high productivity but volatile coastlines, (iii) migratory marine fauna, and (iv) plankton that are the most abundant eukaryotes on earth. Tropical and temperate zones both show impacts of glacial cycles, the former primarily through changing sea levels, and the latter through coastal habitat disruption. The general concordance between biogeography and phylogeography indicates that the population-level genetic divergences observed between provinces are a starting point for macroevolutionary divergences between species. However, isolation between provinces does not account for all marine biodiversity; the remainder arises through alternative pathways, such as ecological speciation and parapatric (semiisolated) divergences within provinces and biodiversity hotspots.
Extraction of natural gas by hydraulic fracturing of the Middle Devonian Marcellus Shale, a major gas-bearing unit in the Appalachian Basin, results in significant quantities of produced water ...containing high total dissolved solids (TDS). We carried out a strontium (Sr) isotope investigation to determine the utility of Sr isotopes in identifying and quantifying the interaction of Marcellus Formation produced waters with other waters in the Appalachian Basin in the event of an accidental release, and to provide information about the source of the dissolved solids. Strontium isotopic ratios of Marcellus produced waters collected over a geographic range of ∼375 km from southwestern to northeastern Pennsylvania define a relatively narrow set of values (εSr SW = +13.8 to +41.6, where εSr SW is the deviation of the 87Sr/86Sr ratio from that of seawater in parts per 104); this isotopic range falls above that of Middle Devonian seawater, and is distinct from most western Pennsylvania acid mine drainage and Upper Devonian Venango Group oil and gas brines. The uniformity of the isotope ratios suggests a basin-wide source of dissolved solids with a component that is more radiogenic than seawater. Mixing models indicate that Sr isotope ratios can be used to sensitively differentiate between Marcellus Formation produced water and other potential sources of TDS into ground or surface waters.
Depression is a global problem, affecting populations worldwide, but is too often under-diagnosed. The identification of depression among patients with diabetes is important because depression is ...prevalent in this group and can complicate diabetes management.
The aim of the study was to determine the sensitivity and specificity of the PHQ-9 in the detection of depression among patients with type-2 diabetes mellitus attending non-communicable diseases (NCD) clinics in Malawi.
We conducted a validation study of the Patient Health Questionnaire (PHQ-9) among 323 patients with type-2 diabetes mellitus who attended two NCD clinics in one of the 28 districts of Malawi. The participants were screened consecutively using the nine-item PHQ-9 in Chichewa by a research assistant and completed a diagnostic interview using the Structured Clinical Interview for DSM-IV (SCID) for depression with a mental health clinician. We evaluated both content validity based on expert judgement and criterion validity of the Patient Health Questionnaire (PHQ-9) based on performance against the SCID. The PHQ-9 cutpoint that maximized sensitivity plus specificity was selected to report test characteristics.
Using the SCID for depression, the prevalence of minor or major depression was 41% (133/323). The internal consistency estimate for the PHQ-9 was 0.83, with an area under the receiver operator curve (AUC) of 0.93 (95% CI, 0.91-0.96). Using the optimal cut-point of ≥9, the PHQ-9 had a sensitivity of 64% and a specificity of 94% in detecting both minor and major depression, with likelihood ratio-positive = 10.1 and likelihood ratio negative =0.4 as well as overall correct classification (OCC) rate of 81%.
This is the first validation study of the PHQ-9 in NCD clinics in Malawi. Depression was highly prevalent in this sample. The PHQ-9 demonstrated reasonable accuracy in identifying cases of depression and is a useful screening tool in this setting. Health care workers in NCD clinics can use the PHQ-9 to identify depression among their patients with those having a positive screen followed up by additional diagnostic assessment to confirm diagnosis.
PACTR201807135104799 . Retrospectively registered on 12 July 2018.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
We conducted a field survey of leaders and their followers to examine factors that moderate the relationship between employee proactive personality and proactive behaviour. As hypothesized, random ...coefficient modelling analysis showed that two situational factors – transformational leadership and a climate of innovation and flexibility – moderated the relationship between employee proactive personality and proactive behaviour. Conceptually, we draw from situational strength theory to predict the pattern of these interactions. Our findings indicated that organizations desiring proactive employee behaviour would be well advised to take one of three courses of action: select employees with proactive personality who will generally behave proactively regardless of the situation; develop transformational leaders who will motivate, inspire, and support proactive employee behaviour; or cultivate a climate of innovation and flexibility which will create a strong situation that fosters proactivity regardless of employee individual differences.
Practitioner points
The modern workplace often demands that employees behave proactively, and our research shows that there are multiple strategies organizations can implement to facilitate employee proactive behaviour.
In particular, our study reveals three ways for organizations to facilitate proactive employee behaviour: (1) recruit and select employees who are high in proactive personality, who will be more apt to naturally engage in proactive behaviour; (2) hire or train leaders to be transformational since transformational leaders will bring about proactive employee behaviour; or (3) create a climate that rewards innovation and flexibility as such a climate will encourage proactive employee behaviour.
In this study, water and whole rock samples from hydraulically fractured wells in the Marcellus Shale (Middle Devonian), and water from conventional wells producing from Upper Devonian sandstones ...were analyzed for lithium concentrations and isotope ratios (δ7Li). The distribution of lithium concentrations in different mineral groups was determined using sequential extraction. Structurally bound Li, predominantly in clays, accounted for 75–91wt.% of total Li, whereas exchangeable sites and carbonate cement contain negligible Li (<3%). Up to 20% of the Li is present in the oxidizable fraction (organic matter and sulfides). The δ7Li values for whole rock shale in Greene Co., Pennsylvania, and Tioga Co., New York, ranged from −2.3 to +4.3‰, similar to values reported for other shales in the literature. The δ7Li values in shale rocks with stratigraphic depth record progressive weathering of the source region; the most weathered and clay-rich strata with isotopically light Li are found closest to the top of the stratigraphic section. Diagenetic illite–smectite transition could also have partially affected the bulk Li content and isotope ratios of the Marcellus Shale.
In Greene Co., southwest Pennsylvania, the Upper Devonian sandstone formation waters have δ7Li values of +14.6±1.2 (2SD, n=25), and are distinct from Marcellus Shale formation waters which have δ7Li of +10.0±0.8 (2SD, n=12). These two formation waters also maintain distinctive 87Sr/86Sr ratios, suggesting hydrologic separation between these units. Applying a temperature-dependent illitilization model to Marcellus Shale, we found that Li concentration in clay minerals increased with Li concentration in pore fluid during diagenetic illite–smectite transition. Samples from north-central Pennsylvania show a much smaller range in both δ7Li and 87Sr/86Sr than those in southwest Pennsylvania. Spatial variations in Li and δ7Li values show that Marcellus formation waters are not homogeneous across the Appalachian Basin. Marcellus formation waters in the northeastern Pennsylvania portion of the basin show a much smaller range in both δ7Li and 87Sr/86Sr, suggesting long term, cross-formational fluid migration in this region. Assessing the impact of potential mixing of fresh water with deep formation water requires establishment of a geochemical and isotopic baseline in the shallow, fresh water aquifers, and site specific characterization of formation water, followed by long-term monitoring, particularly in regions of future shale gas development.
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•Clay minerals are the main sources of Li in organic-rich shales.•Whole shale δ7Li records changes in continental weathering intensity during deposition.•Li-rich formation water resulted from long-term alteration of volcanogenic ash.•Marcellus Shale formation water δ7Li values vary spatially across Appalachian Basin.•δ7Li and 87Sr/86Sr record varying degrees of cross-stratigraphic mixing across the basin.
Episodes of spreading ridge subduction occurred during late Oligocene to early Miocene time along western California and during late Paleocene to early Eocene time along southern Alaska. In each ...case, ridge subduction and subsequent slab window formation has had a profound influence on continental margin magmatism. Foremost, in each setting there was a hiatus in arc magmatism following ridge subduction, followed by the onset of volcanism in zones of local extension within arc-front, forearc, and accretionary prism settings. These near-trench volcanic rocks are distinctive from adjacent arc rocks and represent unique episodes of continental margin magmatism.
The western California volcanic rocks were erupted into several local extensional basins and form discrete volcanic centers within each basin. The southern Alaska volcanic rocks, which form the Caribou Creek volcanic field, were erupted in a broad zone of extension that trended orthogonally to the continental margin. Basalts from the western California volcanic centers and the Caribou Creek volcanic field are tholeiitic and have depleted Nd and Sr isotope compositions with ɛ
Nd(
t) as high as +
9.3 and +
10.9 and
87Sr/
86Sr(
t) as low as 0.70258 and 0.70278, respectively. These basalts are unique because they are the most geochemically depleted basalts yet documented along the continental margin of the northern Cordillera. The basalts of each group also have high Ti contents (TiO
2 above 1.5%) and low ratios of fluid-mobile and other large ion lithophile elements compared to high field strength elements. For example, Ba/Ta ratios among the basalts range from about 40 to 600, with most samples below 270, while arc basalts typically have Ba/Ta ratios greater than 450. The basalts also have Th/Yb and Ta/Yb ratios in the range of mid-ocean-ridge basalts and do not exhibit the typical enrichment in Th/Yb that characterizes arc basalts. The basaltic andesites through dacites and rhyolites have more enriched isotope compositions, with ɛ
Nd(
t) and
87Sr/
86Sr(
t) ranging from +
6.3 to −
3.2 and 0.70390 to 0.71131, respectively, among the western California samples and from +
10.1 to +
7.3 and 0.70299 to 0.70413, respectively, in the southern Alaska Caribou Creek samples. Compared to the basalts, the intermediate to acidic samples of each group also show enrichment in the light rare earth and large ion lithophile elements (e.g., Ba, Rb, Th, K). These data indicate that assimilation of crustal rocks was important in the evolution of each volcanic suite, although in the case of the Caribou Creek volcanic field, the crustal rocks are of oceanic island arc affinity and did not impart a strong geochemical enrichment to the magmas.
The depleted Nd and Sr isotope and trace element compositions, coupled with the relatively high Ti content and low Ba/Ta and Th/Yb ratios among the basalts, indicates that the basalt magmas of each group formed by a low-degree of partial melting from a depleted mantle source without a strong flux of fluid-mobile large ion lithophile elements as would occur above an actively dewatering subducted slab. This petrogenesis is consistent with a slab window model in which parental magmas were derived by decompression melting of suboceanic (sub-slab) mantle that upwelled into the opening that formed beneath each continental margin following spreading ridge subduction.
The Wnt/β-catenin signaling pathway is aberrantly activated in colorectal (CRC) and many other cancers, and novel strategies for effectively targeting it may be needed due to its complexity. In this ...report, SM08502, a novel small molecule in clinical development for the treatment of solid tumors, was shown to reduce Wnt pathway signaling and gene expression through potent inhibition of CDC-like kinase (CLK) activity. SM08502 inhibited serine and arginine rich splicing factor (SRSF) phosphorylation and disrupted spliceosome activity, which was associated with inhibition of Wnt pathway-related gene and protein expression. Additionally, SM08502 induced the generation of splicing variants of Wnt pathway genes, suggesting that its mechanism for inhibition of gene expression includes effects on alternative splicing. Orally administered SM08502 significantly inhibited growth of gastrointestinal tumors and decreased SRSF phosphorylation and Wnt pathway gene expression in xenograft mouse models. These data implicate CLKs in the regulation of Wnt signaling and represent a novel strategy for inhibiting Wnt pathway gene expression in cancers. SM08502 is a first-in-class CLK inhibitor being investigated in a Phase 1 clinical trial for subjects with advanced solid tumors (NCT03355066).
•SM08502 is a potent small-molecule CDC-like kinase (CLK) inhibitor.•SM08502 inhibited the Wnt signaling pathway in vitro and in vivo in colorectal cancer models.•SM08502 affected alternative splicing, which underlies inhibition of aberrant Wnt signaling.•SM08502 demonstrated potent anti-tumor activity in xenograft models of GI cancer.
Biogenic carbonates, including bivalve shells, record past environmental conditions, but their interpretation requires understanding environmental and biological factors that affect trace metal ...uptake. We examined stable barium (δ138Ba) and radiogenic strontium (87Sr/86Sr) isotope ratios in the aragonite shells of four native freshwater mussel species and two invasive species in five streams and assessed the effects of species identity, growth rate, and river water chemistry on shell isotopic composition. Shells were robust proxies for Sr, accurately reflecting 87Sr/86Sr ratios of river water, regardless of species or growth rate. In contrast, shell δ138Ba values, apart from invasive Corbicula fluminea, departed widely from those of river water and varied according to species and growth rate. Apparent fractionation between river water and the shell (Δ138Bashell-water) reached -0.86‰, the greatest offset observed for carbonate minerals. The shell deposited during slow growth periods was more enriched in lighter Ba isotopes than the rapidly deposited shell; thus, this phenomenon cannot be explained by aragonite precipitation kinetics. Instead, biological ion transport processes linked to growth rate may be largely responsible for Ba isotope variation. Our results provide information necessary to interpret water chemistry records preserved in shells and provide insights into biomineralization processes and bivalve biochemistry.Biogenic carbonates, including bivalve shells, record past environmental conditions, but their interpretation requires understanding environmental and biological factors that affect trace metal uptake. We examined stable barium (δ138Ba) and radiogenic strontium (87Sr/86Sr) isotope ratios in the aragonite shells of four native freshwater mussel species and two invasive species in five streams and assessed the effects of species identity, growth rate, and river water chemistry on shell isotopic composition. Shells were robust proxies for Sr, accurately reflecting 87Sr/86Sr ratios of river water, regardless of species or growth rate. In contrast, shell δ138Ba values, apart from invasive Corbicula fluminea, departed widely from those of river water and varied according to species and growth rate. Apparent fractionation between river water and the shell (Δ138Bashell-water) reached -0.86‰, the greatest offset observed for carbonate minerals. The shell deposited during slow growth periods was more enriched in lighter Ba isotopes than the rapidly deposited shell; thus, this phenomenon cannot be explained by aragonite precipitation kinetics. Instead, biological ion transport processes linked to growth rate may be largely responsible for Ba isotope variation. Our results provide information necessary to interpret water chemistry records preserved in shells and provide insights into biomineralization processes and bivalve biochemistry.
Targeted radiopharmaceutical therapy with alpha-particle emitters (αRPT) is advantageous in cancer treatment because the short range and high local energy deposition of alpha particles enable precise ...radiation delivery and efficient tumor cell killing. However, these properties create sub-organ dose deposition effects that are not easily characterized by direct gamma-ray imaging (PET or SPECT). We present a computational procedure to determine the spatial distribution of absorbed dose from alpha-emitting radionuclides in tissues using digital autoradiography activity images from an ionizing-radiation quantum imaging detector (iQID). Data from
At-radioimmunotherapy studies for allogeneic hematopoietic cell transplantation in a canine model were used to develop these methods. Nine healthy canines were treated with 16.9-30.9 MBq
At/mg monoclonal antibodies (mAb). Lymph node biopsies from early (2-5 h) and late (19-20 h) time points (16 total) were obtained, with 10-20 consecutive 12-µm cryosections extracted from each and imaged with an iQID device. iQID spatial activity images were registered within a 3D volume for dose-point-kernel convolution, producing dose-rate maps. The accumulated absorbed doses for high- and low-rate regions were 9 ± 4 Gy and 1.2 ± 0.8 Gy from separate dose-rate curves, respectively. We further assess uptake uniformity, co-registration with histological pathology, and requisite slice numbers to improve microscale characterization of absorbed dose inhomogeneities in αRPT.
Global Li production will require a ∼500 % increase to meet 2050 projected energy storage demands. One potential source is oil and gas wastewater (i.e., produced water or brine), which naturally has ...high total dissolved solids (TDS) concentrations, that can also be enriched in Li (>100 mg/L). Understanding the sources and mechanisms responsible for high naturally-occurring Li concentrations can aid in efficient targeting of these brines. The isotopic composition (δ7Li, δ11B, δ138Ba) of produced water and core samples from the Utica Shale and Point Pleasant Formation (UPP) in the Appalachian Basin, USA indicates that depth-dependent thermal maturity and water-rock interaction, including diagenetic clay mineral transformations, likely control Li concentrations. A survey of Li content in produced waters throughout the USA indicates that Appalachian Basin brines from the Marcellus Shale to the UPP have the potential for economic resource recovery.
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•δ7Li, δ11B, δ138Ba were determined for Utica produced water and core.•Utica and Marcellus produced water δ7Li, δ11B, δ138Ba reflect no differences.•Depth-dependent thermal maturity likely control Li in Utica produced water.•Utica produced water Li is highest where the Mg/Li ratios and δ7Li are lowest.
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