These findings were compared with the NPAs on www.selleckchem.com/products/Y-27632.html the FA images and the logMAR visual acuity (VA). RESULTS. The SD-OCT images showed that most areas of capillary nonperfusion had an indistinct boundary between the NFL and GCL/IPL in DR, regardless

of high or moderate OCT reflectivity. The total transverse length of the NPAs was correlated positively with that of the areas with no boundary between these layers in all 108 eyes (R = 0.860, P smaller than 0.001). Sixty-four eyes that had center-involved diabetic macular edema (DME) also had a significant association between them (R = 0.764, P smaller than 0.001), and the most significant correlation was seen in eyes without DME (R = 0.955, P smaller than 0.001). The macular transverse length of the areas with no boundary between the AZD9291 NFL and GCL/IPL was associated modestly with the logMAR VA (R = 0.334, P smaller than 0.001). The indistinct Henle’s layer on SD-OCT images

often was delineated specifically in the NPAs rather than in the perfused areas. CONCLUSIONS. Nonperfused areas were associated significantly with the absence of a boundary between the NFL and GCL/IPL on SD-OCT images in DR.”
“Competition for limited, cell extrinsic survival factors is a general feature of peripheral selection checkpoints involved in B lymphocyte maturation and activation. Perhaps the best-characterized example involves BLyS (B lymphocyte stimulator), which modulates the size and composition of mature naive B cell pools, but evidence for analogous competitive

checkpoints is emerging for both germinal center B cells and plasma cells. Here we discuss how deliberate alteration of BLyS levels might be used to manipulate B cell repertoire selection in order to restore self-tolerance in autoimmunity, click here remodel the repertoire to accommodate neo-self antigens introduced through transplantation and gene therapy, or expand repertoire diversity to reveal novel, therapeutically useful specificities. (C) 2012 Elsevier B.V. All rights reserved.”
“TIM (T cell, Ig, mucin) proteins can regulate T cell immune responses. Tim-4 mRNA is not expressed in T cells, but exclusively in APCs. Tim-4 is a ligand for Tim-1 and Tim-4.Ig fusion protein was shown to either inhibit or expand T cells. However, the molecular basis for such opposite effects was not defined. By generating mAbs, we show that expression of Tim-4 protein is restricted to CD11c(+) and CD11b(+) cells and is up-regulated upon activation. We show that Tim-4 specifically phosphorylates Tim-1 and induces T cell expansion by enhancing cell division and reducing apoptosis. Tim-4 also induces the phosphorylation of signaling molecules LAT, Akt, and ERK1/2 in T cells. Tim-4, expressed on APCs, is a costimulatory molecule that promotes T cell expansion and survival by cross-linking Tim-1 on T cells.

Moreover, significantly higher number

of total protein spots https://www.selleckchem.com/products/p5091-p005091.html and protein peaks were detected in NSAIDs and mixtures abusers.\n\nConclusions: These findings confirm the presence of alterations in proteins excretion in MOH patients. Analysis of urinary proteins by powerful proteomic technologies could lead to the discovery of early candidate biomarkers, that might allow to identify MOH patients prone to develop potential drug overuse-induced nephrotoxicity.”
“Introduction: We undertook a systematic review and narrative synthesis of the literature to identify how professionalism is defined in the medical education literature. Methods: Eligible studies included any articles published between 1999 and 2009 inclusive presenting viewpoints, opinions, or empirical research on defining medical professionalism. Results: We identified 195 papers on the topic of definition of professionalism in medicine. Of these, we rated 26 as high quality and included these in the narrative synthesis. Conclusion: As yet there is no overarching conceptual context of medical professionalism that is universally agreed upon. The continually shifting nature of the organizational and social milieu in which medicine operates creates a dynamic situation where no definition has yet taken AS1842856 order hold as definitive.”
“The food-borne

pathogen Vibrio parahaemolyticus has been reported as being present in New Zealand (NZ) seawaters, but there have been no

reported outbreaks of food-borne infection from commercially grown NZ seafood. Our study determined the current incidence of V. parahaemolyticus in NZ oysters and Greenshell mussels and the prevalence of V. parahaemolyticus tdh and trh strains. MLN2238 supplier Pacific (235) and dredge (21) oyster samples and mussel samples (55) were obtained from commercial shellfish-growing areas between December 2009 and June 2012. Total V. parahaemolyticus numbers and the presence of pathogenic genes tdh and trh were determined using the FDA most-probable-number (MPN) method and confirmed using PCR analysis. In samples from the North Island of NZ, V. parahaemolyticus was detected in 81% of Pacific oysters and 34% of mussel samples, while the numbers of V. parahaemolyticus tdh and trh strains were low, with just 3/215 Pacific oyster samples carrying the tdh gene. V. parahaemolyticus organisms carrying tdh and trh were not detected in South Island samples, and V. parahaemolyticus was detected in just 1/21 dredge oyster and 2/16 mussel samples. Numbers of V. parahaemolyticus organisms increased when seawater temperatures were high, the season when most commercial shellfish-growing areas are not harvested. The numbers of V. parahaemolyticus organisms in samples exceeded 1,000 MPN/g only when the seawater temperatures exceeded 19 degrees C, so this environmental parameter could be used as a trigger warning of potential hazard. There is some evidence that the total V.

We evaluated the reliability of spatio-temporal variables and body angles (lower-limb joints, trunk and pelvis angles) during two sessions of 3DGA using intra-class correlation coefficients (ICC). The minimum number of trials needed to overcome intrinsic variability was evaluated using an exponential fit model and the Bland and Altman coefficient of repeatability Selleck PLX3397 (CoR). The accuracy of measurement was evaluated using a manual goniometer and the recording of 18 different angles.\n\nResults: Spatio-temporal variables

and most of the kinematic joint and trunk angles calculated demonstrated good to excellent reliability (ICC from 0.77 to 0.97). This was not the case for pelvic angles. The fitting model combined with the CoR showed that 5-10 trials are sufficient to obtain good reliability [ICC > 0.7; CoR < 2 standard deviation (SD)] for most of the spatio-temporal variables. All body angles showed good reliability (ICC > 0.7) and low CoR (< 2 SD) after five trials except for the pelvic angles. The reliability of marker positioning was found to be good (ICC > 0.7) to excellent (ICC > 0.9). Differences between angles measured using 3DGA and angles measured with a manual goniometer were found to be less than one percent.\n\nConclusion: The present study shows that most of variables obtained using

3DGA in hip OA patients are reliable. Moreover, for most variables, 5-10 trials are needed to obtain good reliability and to overcome intrinsic variability, rather than 30 or more, thus improving the feasibility Selisistat of measurement. (C) 2010 Osteoarthritis Research Society International. Published by Elsevier Ltd. All rights

reserved.”
“Objective\n\nTo measure vascular endothelial growth factor (VEGF) levels in aqueous humor, serum, and plasma in diabetic CYT387 ic50 and nondiabetic cataractous dogs.\n\nMethods\n\nCanine VEGF was assayed in the plasma and serum of 32 dogs (20 diabetics; 12 nondiabetics) and aqueous humor in 57 eyes of those dogs (39 diabetic; 18 nondiabetic) undergoing phacoemulsification, using a commercial canine VEGF assay. Statistical analysis was performed using Fisher’s PLSD, t-test, and regression analysis to compare values by diabetic status, duration of diabetes, age, weight, gender, left vs. right eye, and blood clarity.\n\nResults\n\nPlasma, but not serum or aqueous humor VEGF values of diabetics were significantly greater than nondiabetics (P = 0.019). Older nondiabetics (10-15 years) had higher plasma VEGF values than younger (0-5 and 5-10 years) dogs (P = 0.0002 and 0.0001, respectively). There was no significant difference in aqueous humor VEGF between left and right eyes in all patients. Serum and plasma, but not aqueous humor, VEGF values in females were significantly higher than males in both groups.\n\nConclusion\n\nSimilar to human diabetic patients, VEGF aqueous humor values in all dogs are significantly higher than blood values.

Conclusion: HDAC inhibitor Exposure to violence needs to be examined in a multi-faceted manner: i) as discrete distal and proximal events, which may have distinct patterns of association with mental health and ii) as a concept with different but overlapping dimensions, thus also accounting for possible cumulative effects.”
“Background: Ceftaroline is a new parenteral cephalosporin agent with excellent activity against methicillin-sensitive (MSSA) and resistant strains of Staphylococcus aureus (MRSA). Critically ill surgical patients are susceptible to infection, often by multi-drug-resistant pathogens. The activity of ceftaroline against such pathogens has not been

described. Methods: Three hundred thirty-five consecutive microbial isolates were collected from surgical wounds or abscesses, respiratory, urine, and blood cultures from patients in the surgical intensive care unit (SICU) of a major tertiary medical center. Using Clinical and Laboratory Standards Z-DEVD-FMK solubility dmso Institute (CLSI) standard methodology and published breakpoints, all aerobic, facultative anaerobic

isolates were tested against ceftaroline and selected comparative antimicrobial agents. Results: All staphylococcal isolates were susceptible to ceftaroline at a breakpoint of smaller than = 1.0 mcg/mL. In addition, ceftaroline exhibited excellent activity against all streptococcal clinical isolates and non-ESBL-producing strains of Enterobacteriaceae (93.5%) recovered from SICU patients. Ceftaroline was inactive against ESBL-producing

Enterobacteriaceae, Pseudomonas aeruginosa, vancomycin-resistant find more enterococci, and selective gram-negative anaerobic bacteria. Conclusions: At present, ceftaroline is the only cephalosporin agent that is active against community and healthcare-associated MRSA. Further studies are needed to validate the benefit of this novel broad-spectrum anti-infective agent for the treatment of susceptible serious infections in the SICU patient population.”
“Nonobese Diabetic (NOD) mice are susceptible strains for Type 1 diabetes development, and Nonobese Diabetes-Resistant (NOR) mice are defined as suitable controls for NOD mice in non-MHC-related research. Diabetes is often accelerated in NOD mice via Streptozotocin (STZ). STZ is taken inside cells via GLUT2 transmembrane carrier proteins, the major glucose transporter isoforms in pancreatic beta cells, liver, kidneys, and the small intestine. We observed severe adverse effects in NOR mice treated with STZ compared to NOD mice that were made diabetic with a similar dose. We suggested that the underlying mechanism could be differential GLUT2 expressions in pancreatic beta cells, yet immunofluorescent and immunohistochemical studies revealed similar GLUT2 expression levels.

Further

analyses are necessary to explain the interaction between neuropeptides and the immune system. (J. Endocrinol. Invest. 32: 123-129, 2009) (C) 2009, Editrice Kurtis”
“Ten complete mammalian genome sequences were compared by using the “feature frequency profile” (FFP) method of alignment-free comparison. This comparison technique reveals that the whole nongenic portion of mammalian genomes contains evolutionary information that check details is similar to their genic counterparts-the intron and exon regions. We partitioned the complete genomes of mammals (such as human, chimp, horse, and mouse) into their constituent nongenic, intronic, and exonic components. Phylogenic species trees were constructed for each individual component class of genome sequence data as well as the whole genomes by using standard tree-building algorithms with FFP distances. The phylogenies of the whole genomes and each of the component classes (exonic, find more intronic, and nongenic regions) have similar topologies, within

the optimal feature length range, and all agree well with the evolutionary phylogeny based on a recent large dataset, multispecies, and multigene-based alignment. In the strictest sense, the FFP-based trees are genome phylogenies, not species phylogenies. However, the species phylogeny is highly related to the whole-genome phylogeny. Furthermore, our results reveal that the footprints of evolutionary history are spread throughout

the entire length of the whole genome of an organism and are not limited to genes, introns, or short, highly conserved, nongenic sequences that can be adversely affected by factors (such as a choice of sequences, homoplasy, and different mutation rates) resulting in inconsistent species phylogenies.”
“Our Pfizer Licensed Compound Library goal in these analyses was to use genomic features from a test set of primary breast tumors to build an integrated transcriptome landscape model that makes relevant hypothetical predictions about the biological and/or clinical behavior of HER2-positive breast cancer. We interrogated RNA-Seq data from benign breast lesions, ER+, triple negative, and HER2-positive tumors to identify 685 differentially expressed genes, 102 alternatively spliced genes, and 303 genes that expressed single nucleotide sequence variants (eSNVs) that were associated with the HER2-positive tumors in our survey panel. These features were integrated into a transcriptome landscape model that identified 12 highly interconnected genomic modules, each of which represents a cellular processes pathway that appears to define the genomic architecture of the HER2-positive tumors in our test set. The generality of the model was confirmed by the observation that several key pathways were enriched in HER2-positive TCGA breast tumors.

When the step edges are perpendicular to the incident beam azimuth, the atomic density is the primary origin and the

step density is a subsidiary one. When the step edges are parallel to the incident beam azimuth, the step density is the primary origin and the atomic density is a subsidiary one.”
“A disproportionately large number of young (<50 years) black patients present with colorectal cancer (CRC) in South Africa. Although a phenomenon previously described elsewhere in Africa, its specific molecular basis, whether sporadic or hereditary, has not been established. Molecular analysis of these tumours could link them CA3 ic50 to the features known to be associated with specific types of hereditary colorectal cancer, specifically through examination of levels of microsatellite instability, promoter methylation and the presence or absence of KRAS and BRAF mutations. The molecular features of cancer tissue samples from 44 CRC cases of black and

white patients in South Africa were accordingly retrospectively analysed without knowledge of family history. Compared with samples from older blacks (>50 years), those from young black patients presented more often with a low methylation phenotype (CIMP-L) and high levels of microsatellite instability Linsitinib cell line (MSI-H). Furthermore, as determined by real-time PCR using probe technology, the tissues from 35% of young blacks showed mutations within exon 1 of the KRAS gene. The BRAF-V600E mutation was only evident in the case of a single young black patient. Based on these results it seems likely that a proportion of CRC cases in young black patients from South Africa develop through the accumulation of mutations Cell Cycle inhibitor resulting in a mismatch repair deficiency linked to MSI-H and, possibly, germline mutations in the mismatch repair genes. The features in these patients are consistent with a diagnosis of the Hereditary Non-Polyposis Colorectal Cancer (HNPCC) syndrome. This finding has important Implications for patient management and suggests that family members may be at high risk for CRC.”
“Several polyacrylonitrile (PAN)/tea polyphenol (TP) blends were prepared with various mixing weight ratios (percentage). With a

commercial acrylonitrile-butadiene-styrene (ABS) as reference, the results show that the PAN/TP blends with 12.5 wt % TP had a better antiwear ability and similar hardness to those of ABS. All of the prepared PAN/TP blends showed a lower impact strength than the referenced ABS. However, some values were indeed higher than those reported for engineering materials in the literature, for example, polystyrenes and some ABS blends. Differential scanning calorimetry, differential thermogravimetry, and dynamic mechanical analysis indicated that the PAN/TP blends had enhanced the thermal stability compared to the pure PAN. Fourier transform infrared spectral analysis suggested that the H bonds increased in the PAN/TP blends. (c) 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci.

Pretreatment of the 42-residue A beta fragment (A beta(1-42)) with the ubiquitous brain carbohydrates, glucose, fructose, and the GAG chondroitin

sulfate B (CSB) inhibits A beta beta(1-42)-induced apoptosis and reduces the peptide neurotoxicity on neuroblastoma cells, a cytoprotective effect that is partially reverted by AGE inhibitors such as pyridoxamine and L-carnosine. Thioflavin T fluorescence measurements indicate that at concentrations close to physiological, only CSB promotes the formation of A beta amyloid fibril structure. Atomic force microscopy imaging and Western blot analysis suggest that glucose favours the formation of globular oligomeric structures derived from aggregated species. Our data suggest that at short times carbohydrates CH5183284 research buy reduce A beta(1-42) toxicity through different mechanisms both dependent and independent of AGE formation.”
“Background: In the treatment of nail psoriasis, standardized therapeutic regimens are currently lacking. Objective: To evaluate the therapeutic efficacy of indigo naturalis oil extract in patients with nail psoriasis. Cilengitide Methods: Patients with nail psoriasis applied indigo naturalis oil extract on affected

nails twice daily for 24 weeks. Efficacy was evaluated using the Nail Psoriasis Severity Index (NAPSI) and modified target NAPSI for the single most severely affected nail. Results: Twenty-eight out of 32 patients completed the study. The mean NAPSI was 36.1 +/- 14.7 at baseline and decreased to 14.9 +/- 11.1 at week 24 while the mean modified target NAPSI was 11.7 +/- 3.9 at baseline and decreased to 3.6 +/- 3.2 at week 24. Conclusions: Indigo naturalis oil extract appeared to improve nail psoriasis. Although preliminary, these results indicate that it could provide a novel therapeutic option for nail psoriasis, a disease notoriously difficult to treat. Copyright (C) 2011 S. Karger

AG, Basel”
“The renal outer medullary potassium channel (ROMK, or Kir1.1, encoded by KCNJ1) critically regulates renal tubule electrolyte and water transport and hence blood volume and pressure. Selleck MAPK Inhibitor Library The discovery of loss-of-function mutations in KCNJ1 underlying renal salt and water wasting and lower blood pressure has sparked interest in developing new classes of antihypertensive diuretics targeting ROMK. The recent development of nanomolar-affinity small-molecule inhibitors of ROMK creates opportunities for exploring the chemical and physical basis of ligand-channel interactions required for selective ROMK inhibition. We previously reported that the bis-nitro-phenyl ROMK inhibitor VU591 exhibits voltage-dependent knock-off at hyperpolarizing potentials, suggesting that the binding site is located within the ion-conduction pore.

She was being treated with long-term haemodialysis (HD) and Vorinostat supplier underwent two kidney transplants with transplantectomies. The patient presented with severe SHPT caused by parathyroid gland hypertrophy. The radiology test showed signs of VC in the radial and interdigital arteries, and VC in a linear arrangement were observed in both breasts on the mammography. Cinacalcet

was added to her treatment with vitamin D derivatives and phosphate-binding agents, which resulted in a good control of mineral metabolism. The radiology test showed that the calcification in the interdigital artery had disappeared and that the bone appeared to be more structured. The mammography also showed regression of the VC. To conclude, cinacalcet may have potential for regression of VC in patients with SHPT”
“Successful settlement of pelagic fish larvae into benthic juvenile Selleckchem Bcl-2 inhibitor habitats may be enhanced by a shortened settlement period, since it limits larval exposure to predation in the new habitat. Because the spatial distribution of marine fish larvae immediately prior to settlement versus during settlement was unknown, field experiments were conducted at Ishigaki Island (Japan) using light trap sampling and underwater visual belt transect surveys to investigate the spatial distribution patterns of

selected pre- and post-settlement fishes (Acanthuridae, Pomacentridae, Chaetodonidae and Lethrinidae) among four habitats (seagrass bed, coral rubble, branching coral and tabular coral). The results highlighted two patterns: patterns 1, pre- and post-settlement individuals showing a ubiquitous distribution among the four habitats (Acanthuridae) and pattern 2, pre-settlement

individuals distributed in all habitats, but post-settlement individuals restricted to coral (most species of Pomacentridae and Chaetodontidae) or seagrass habitats (Lethrinidae). The first pattern minimizes the transition time between the larval pelagic stage and acquisition of a benthic reef Vactosertib inhibitor habitat, the latter leading immediately to a juvenile lifestyle. In contrast, the second pattern is characterized by high settlement habitat selectivity by larvae and/or differential mortality immediately after settlement.”
“Formation and coexistence of tricalcium silicate (C(3)S) and calcium sulphoaluminate (C(4)A(3)(S) over bar) minerals in Portland cement clinker containing calcium sulphoaluminate were investigated. The f-CaO content, mineral composite and formation of mineral in the clinker were analyzed respectively by chemical analysis, differential scanning calorimetry(DSC) and X-ray diffraction. The results show that, adding a suitable amount of BaO can improve the burnability of raw meal and promote the f-CaO absorption. Tricalcium silicate and calcium sulphoaluminate minerals can form and coexist in clinkers at 1 234-1 317 degrees C by the addition of BaO to the raw meal. A suitable amount of BaO expanded. the coexistence temperature of two minerals by 58 degrees C.

\n\nTherefore we studied the effects of the oximes obidoxime, HI 6 and MMB-4 on the rate of decarbamylation for physostigmine- and pyridostigmine-inhibited human erythrocyte AChE both in a dynamically working in vitro model and a static cuvette system.\n\nOur results show that HI 6 increased the rate of decarbamylation for both physostigmine and pyridostigmine-inhibited enzyme in both systems, the observed effect by HI 6 increasing

with higher doses. Obidoxime had a slightly accelerating effect on the pyridostigmine-inhibited enzyme. MMB-4 applied to pyridostigmine-inhibited AChE in the static system only showed no difference to the experiments made in absence of oxime. No oxime showed a tendency to retard the rate LB-100 price of decarbamylation. (c) 2008 Elsevier Inc. All rights PARP activation reserved.”
“Laser welding has the potential to become an effective method for wound closure and healing without sutures. Closure of skin incisions by laser welding with a combination of two near-infrared lasers (980 and 1064 nm), was performed for the first time in this study. One centimeter long, full-thickness incisions were made on the Wistar rat’s dorsal skin. The efficiencies

of laser-welding with different parameters were investigated. Incision-healing, histology examination, and a tensile strength test of incisions were recorded. Laser welding with the irradiance level of 15.9 W/cm(2) for both 980 and 1064-nm lasers and exposure time of 5 s per spot in continuous wave mode yielded a more effective closure and healing

with minimal thermal damage, faster recovery, and stronger apposition in comparison with a suturing technique. The conclusion is that skin welding with a combination of two near-infrared diode lasers can be a good candidate for incision closure, and further investigations are in progress for clinical use. (C) 2011 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOI: 10.1117/1.3552648]“
“Persistent levels of IL-10 play a central role in progressive immune dysfunction associated with chronic viral infections such as HIV, but the underlying mechanisms are poorly understood. Because IL-10 affects the phenotypic and functional properties of DCs, which are responsible for initiating adaptive immune responses, we MK-2206 investigated whether IL-10 induces changes in DC phenotype and function in the context of HIV infection. Here, we show that IL-10 treatment of immature and mature human DCs in culture induced contrasting phenotypic changes in these populations: immature DCs exhibited aberrant resistance to NK cell-mediated elimination, whereas mature DCs exhibited increased susceptibility to NKG2D-dependent NK elimination. Treatment of immature and mature DCs with HIV resulted in potent IL-10 secretion and the same phenotypic and functional changes observed in the IL-10-treated cells.

Four SPs were derived from hemolysin of Escherichia coli, RTX protein of V. cholerae, hemolysin of V. anguillarum, zinc-metalloprotease of V. anguillarum, respectively, and their abilities to support secretion of green fluorescent protein (GFP) in an attenuated

V. anguillarum strain MVAV6203 were assayed. Immunodetection of GFP showed that the capability of the tested signal leaders to direct secretion of GFP varied greatly. Although all the four signal peptide-fused GFPs could be expressed correctly and trapped intracellularly in recombinant strains, only the EmpA signal peptide could confer efficient MK-4827 secretion to GFP. For the investigation of its potential application in live bacteria carrier vaccines, a heterologous protein EseB of Edwardsiella tarda was fused to the SP (empA) antigen-delivery system and introduced into the strain MVAV6203. Further analysis of EseB demonstrated that the constructed SP (empA) antigen-delivery Quizartinib in vivo system could be used to secrete foreign protein

in attenuated V. anguillarum and be available for carrier vaccines development.”
“(Z)-2-amino-1,5-dihydro-1-methyl-5-[4-(mesyl)benzylidene]-4H-imidazol-4-one mesilate (ZLJ-601) is an imidazolone COX/5-LOX inhibitor, which has excellent anti-inflammatory activity with an improved gastrointestinal safety profile. The purpose of this study was to evaluate the in vivo absorption, distribution, metabolism, and excretion of ZLJ-601 in Sprague-Dawley rats. After intravenous or intragastric administration to rats, the concentration of ZLJ-601 in plasma, bile, urine, feces and various types of tissues was detected by LC-MS. We also conducted the identification of metabolites using tandem mass spectrometry. After the intravenous administration, the t(1/2) ranged Selleck GSK2879552 from 38.71 to 42.62 min and the AUC increased in a

dose-proportional manner. After oral dosing, the plasma level of ZLJ-601 peaked at 28.33 min, having a C-max value of 0.26 mg/l, and the bioavailability was only 4.92%. The highest tissue concentration of ZLJ-601 was observed in lung and kidney, but it was not found in brain. The majority of unchanged ZLJ-601 was excreted in urine (similar to 35.87%) within 36 h. Two main metabolites are the hydroxylation product and the glucuronide conjugate of the hydroxylation product. Copyright (C) 2012 S. Karger AG, Basel”
“Spatial diversity gradients are a pervasive feature of life on Earth. We examined a global ocean circulation, biogeochemistry, and ecosystem model that indicated a decrease in phytoplankton diversity with increasing latitude, consistent with observations of many marine and terrestrial taxa. In the modeled subpolar oceans, seasonal variability of the environment led to competitive exclusion of phytoplankton with slower growth rates and lower diversity.