Plasma clearance of the radiopharmaceutical can be directly measu

Plasma clearance of the radiopharmaceutical can be directly measured from serial plasma samples, as in the horse, or by measuring changes in cardiac blood pool activity by region of interest analysis of images. The objective of this paper is to present a summary of the reported applications of hepatobiliary scintigraphy in veterinary medicine. Semin Nucl Med 44:15-23 (C) 2014 Elsevier Inc. All rights reserved.”
“Surgery for gastrointestinal stromal tumor (GIST) at the duodenojejunal junction is a technically challenging and difficult procedure because of the anatomical complexity. When it comes to laparoscopic surgery, it is more challenging than open surgery.

This study aimed to introduce our laparoscopic procedure JPH203 clinical trial and to evaluate its clinical implication by comparing with open procedures. Between 2003 and 2013, 19 patients underwent segmental resection for a GIST at the duodenojejunal junction: laparoscopic segmental resection with side-to-side duodenojejunostomy (n = 8) and open surgery (n = 11). Clinicopathological findings, operation details, and postoperative outcomes were compared. Both groups were comparable in demographics and clinicopathological characteristics. Postoperative hospital stay of the laparoscopic group (6.3 days) was significantly shorter than the open group (15.7 days, P = 0.008) while no significant MDV3100 Endocrinology & Hormones inhibitor differences

were observed regarding estimated blood loss, operation time, and morbidity. All patients in both groups underwent curative resection without operative mortality. Two patients experienced recurrence after open surgery whereas none of the patients after laparoscopic duodenojejunostomy had recurrence with a median follow-up period of 36 ICG-001 months. Laparoscopic segmental resection with side-to-side duodenojejunostomy for a GIST at the duodenojejunal junction is a safe, feasible, and effective alternative to open approach, providing benefits of minimally invasive surgery.”
“Biofuels have great potential as low-carbon transportation fuel

alternatives and can be essentially drop-in fuels for existing fossil-fuel-based transportation infrastructures. Thus, the incentives for biofuel development are large but there are a number of issues: competition with food, land use, fresh water use, economics in comparison to fossil fuels, and achievable reduction in carbon footprint in comparison to other transportation fuel options. This paper focuses on utilization of anthropogenic CO2 from power plants in advanced biofuel production systems and the integration of those systems with various power plant designs. In doing so, the boundary of the life cycle analysis is expanded to include the power plant CO2 source, considering specifically natural gas, pulverized coal, supercritical coal, and IGCC (integrated gasification combined cycle) options.

“Pulvinaria urbicola Cockerell,

a pulvinariine sof

“Pulvinaria urbicola Cockerell,

a pulvinariine soft scale (Hemiptera: Coccidae), is a broad host-plant generalist, produces honeydew and is commonly tended by ants, including the invasive yellow crazy ant Anoplolepis gracilipes Smith and big-headed ant Pheidole megacephala (Fabricius). Pu. urbicola is implicated in dieback of forest dominated by Pisonia grandis (Nyctaginaceae) on many Indo-Pacific islands. Here we report detection of Pu. urbicola on Christmas DNA Damage inhibitor Island (Indian Ocean), describe the potential impacts of the association of this trophobiont with introduced ants, and briefly outline biosecurity and management issues. On Christmas Island, Pu. urbicola represents a threat to stands of Pi. grandis, potentially threatens the dominant forest tree Pi. umbellifera, and could exacerbate supercolony

formation and impacts of the yellow crazy ant. (C) 2013 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Published by Elsevier B.V. All rights reserved.”
“The aim of the present study was investigate the impact of seawater immersion on peripheral nerve injury and the underlying mechanisms. A total of 234 specific pathogen-free Sprague-Dawley male rats were randomly divided into a sham group, injury control group and seawater immersion + injury group. The Sciatic Functional Index (SFI) was used to assess nerve function for 6 weeks after injury. Compound muscle action potentials were measured and hematoxylin and eosin (H&E) staining of nerve specimens was carried out at week 6. Levels of reactive Dinaciclib cost oxygen species (ROS) and malondialdehyde (MDA) in nerve tissues were measured by enzyme-linked immunosorbent assay (ELISA), and the expression levels of inducible nitric oxide synthase (iNOS) mRNA and protein were measured by reverse transcription-quantitative polymerase chain reaction and immunohistochemistry, respectively. The SFI value in the seawater immersion + injury group after 6 weeks was lower

than that in the injury control group (P smaller than 0.05). The compound muscle action potential in the seawater SCH727965 immersion + injury group had a prolonged latency, and the amplitude and nerve conduction velocity were decreased compared with those in the other groups (P smaller than 0.05). H&E staining demonstrated that nerve fiber regeneration was worse in the seawater immersion + injury group. The ROS and MDA levels in the seawater immersion + injury group were higher than those in the other groups (P smaller than 0.05). The expression levels of iNOS mRNA and protein gradually increased in the injury and seawater immersion + injury groups and peaked at 48 h after surgery. Immersion in seawater further aggravated sciatic nerve injury and led to worse neuronal recovery. The mechanism may be associated with oxidative stress.

This carboxy terminus transactivation domain was found to prefere

This carboxy terminus transactivation domain was found to preferentially regulate genes involved in cell cycle progression. Moreover,

its activity is regulated throughout the cell cycle and modified by protein kinase C-dependent phosphorylation at serine check details residue 388. Our results suggest that this novel post-translational modification within the p73 carboxy terminus transactivation domain is involved in the context-specific guidance of p73 toward the selective induction of cell cycle arrest.”
“Objective. To investigate whether the health and functioning of the Baby Boom generation are better or worse than those of previous cohorts in middle age.\n\nMethods. Trend analysis of vital statistics and self-reports from the National Health Interview Survey for the 40-59 population. Specific outcomes (years of data): mortality (1982-2004); poor or fair health (1982-2006); nine conditions (1997-2006); physical functional limitations (1997-2006); and needing help with personal care, routine needs, or either (1997-2006).\n\nResults. In 2005, the mortality rate of 59-year-olds, the leading edge of the Baby Boom, was 31% lower than that of 59-year-olds in 1982 (8.3 vs. 12.1 per 1,000). There was a similar proportional PF-03084014 decline in

poor/fair health, but the decline reversed in the last decade. From 1997 to 2006, the prevalence of reports of four conditions increased significantly, but this trend may reflect improvements in diagnosis and treatment. Functional limitations and need for help with routine needs were stable, but the need for help with personal care, while quite low, increased.\n\nDiscussion. Trends varied by indicator, period, and age. FK228 mw It is surprising that, given the socioeconomic, medical, and public health advantages of Baby Boomers throughout their lives, they are not doing considerably better on all counts.”
“Background: Tomato spotted wilt virus (TSWV) has a very wide host range, and is transmitted in a persistent manner by several species of thrips. These characteristics make this virus difficult to control. We show here that the over-expression of the mitochondrial

alternative oxidase (AOX) in tomato and petunia is related to TSWV resistance.\n\nResults: The open reading frame and full-length sequence of the tomato AOX gene LeAox1au were cloned and introduced into tomato ‘Healani’ and petunia ‘Sheer Madness’ using Agrobacterium-mediated transformation. Highly expressed AOX transgenic tomato and petunia plants were selfed and transgenic R1 seedlings from 10 tomato lines and 12 petunia lines were used for bioassay. For each assayed line, 22 to 32 tomato R1 progeny in three replications and 39 to 128 petunia progeny in 13 replications were challenged with TSWV. Enzyme-Linked Immunosorbent Assays showed that the TSWV levels in transgenic tomato line FKT4-1 was significantly lower than that of wild-type controls after challenge with TSWV.

Although success can be expected in greater than 90% of these sur

Although success can be expected in greater than 90% of these surgical patients, the optimal postoperative sedation management remains challenging.”
“An SIS epidemic model in two competing species with the mass action

incidence is formulated and analysed. Thresholds for the existence of boundary equilibria are identified and conditions for their local asymptotic stability or instability are found. By persistence theory, conditions for the persistence of either CFTRinh 172 hosts or pathogens are proved. Using Hopf bifurcation theory and numerical simulations, some aspects of the complicated dynamic behaviours of the model are shown: the system may have zero up to three internal equilibria, may have a stable limit cycle, may have three stable attractors. Through the results on persistence and stability of the boundary equilibria, some important interactions IPI-145 concentration between infection and competition are revealed: (1) a species that would become extinct without the infection, may persist in presence of the infection; (2) a species that would coexist with its competitor without the infection, is driven to extinction by the infection; (3) an infection that would die out in either species without the interinfection of disease, may persist in both species in presence of this factor. (C) 2007 Elsevier Ltd. All rights reserved.”

This study aimed to compare hostility, impulsivity, and behavior inhibition between women with and without premenstrual dysphoric disorder (PMDD) during both luteal and follicular phases and to examine whether these variables contribute to irritability and daily functional impairment of PMDD.\n\nMethods: PMDD was screened via the Premenstrual Symptoms Screening Tool. A diagnosis of PMDD was confirmed by psychiatric interviewing without 2-month prospective confirmation. Sixty FLT3 inhibitor women in the PMDD group and 60 women in the control group completed the Chinese Version of the Buss-Durkee Hostility Inventory-Short Form, Dickman’s Impulsivity

Inventory, and the Behavior Inhibition System Scale during the luteal and follicular phases.\n\nResults: We found that the PMDD group had significantly higher levels of hostility, dysfunctional impulsivity, and behavioral inhibition than the control group in both luteal and follicular phases. The PMDD group also had more premenstrual aggravation on total hostility, hostility affect, and suppressive hostility than the control group. Higher hostility, dysfunctional impulsivity, and behavior inhibition were associated with more severe irritability and functional impairment of PMDD.\n\nDiscussion: Hostility, impulsivity, and behavior inhibition might contribute to irritability and functional impairment in women with PMDD.\n\nConclusion: Assessment and interventions based on these factors should be provided for women with PMDD, especially in the luteal phase.

If preexposure prophylaxis is used, precautions similar to those

If preexposure prophylaxis is used, precautions similar to those in the current heterosexual

preexposure prophylaxis trials would be recommended, and the unknown risks of preexposure prophylaxis used during conception and early fetal development should be considered. Anecdotal reports suggest that oral preexposure prophylaxis use is already occurring. It is time to have open discussions of when and how preexposure prophylaxis might be indicated for HIV-discordant couples attempting conception.”
“Hippocampal neurons of neonatal rats were cultured in serum-free culture medium for 5 days in vitro, and treated AZD5582 Apoptosis inhibitor with the Rho-kinase inducer lysophosphatidic acid. Atomic force microscopy revealed that the numbers of level-1, -2 and -3 neurites protruding from rat hippocampal neurons was significantly reduced. After treatment with the Rho

kinase inhibitor Y27632, a significant increase in the numbers of these neurites was observed. Our experimental findings indicate that the Rho-kinase pathway is closely associated with the neurites of hippocampal neurons.”
“ObjectiveRecent genome-wide association studies (GWAS) have identified 3 loci in or near PRDM16 (1p36.32, rs2651899), LRP1 (12q13.3, rs11172113) and TRPM8 (2q37.1, rs10166942) in the population-based Women’s Genome Health Study (WGHS) of migraine, and 2 loci in or near TRPM8 and LRP1 were repeated in European GWAS study. To evaluate whether

the same variants are related to migraine in Chinese population, we investigated migraine with aura (MA) Small molecule library supplier and migraine without aura (MO) patients of Chinese Selleck PRIMA-1MET Han ethnicity in mainland China.\n\nMethodsA case-control study in a cohort of 207 migraine cases and 205 ethnically matched controls was conducted by using the dual-color fluorescence resonance energy transfer (FRET) probes analysis.\n\nResultsThe genotypes of all polymorphisms in 2 groups followed the Hardy-Weinberg equilibrium. We found significant differences in allele distribution of rs2651899 variant in PRDM16 between MO patients and control subjects (P=.049, OR=1.335, 95%CI 1.001-1.782), and there were no difference between MA patients and controls in the frequency of genotype and allele. Also, no significant differences in genotypic and allelic distributions between MA or MO patients and controls were observed in the polymorphisms of rs10166942 of TRPM8 and rs11172113 of LRP1, and there was no significant difference comparing male with female in all loci.\n\nConclusionOur data suggested that rs2651899 variant in PRDM16 plays a potential role in Chinese MO migraine susceptibility, and gender may not play a role.”
“Land use can alter the phosphorus (P) pool in soil. Understanding detailed P changes derived from different land uses is important for sustainable development of soil resources.

(C) 2014 Wiley Periodicals, Inc “
“Background: The Institute

(C) 2014 Wiley Periodicals, Inc.”
“Background: The Institute of Cognitive Neurology (INECO) Frontal Screening (IFS) is a brief neuropsychological tool recently devised for the evaluation of executive dysfunction in neurodegenerative conditions. Objective: In this study we present a cross-cultural validation of the IFS for the Selleck DMXAA Portuguese population, provide normative

values from a healthy sample, determine how age and education affect performance, and inspect its clinical utility in the context of Alzheimer’s disease (AD). A comparison with the Frontal Assessment Battery (FAB) was undertaken, and correlations with other well-established executive functions measures were examined. Methods: The normative sample included 204 participants varying widely in age (20-85 years) and education (3-21 years). The clinical sample (n = 21) was compared with a sample of age-and

education-matched controls (n = 21). Healthy participants completed the IFS and the Mini-Mental State Examination (MMSE). In addition to these, the patients (and matched controls) completed the FAB and a battery of other executive tests. SNX-5422 concentration Results: IFS scores were positively affected by education and MMSE, and negatively affected by age. Patients underperformed controls on the IFS, and correlations were found with the Clock Drawing Test, Stroop test, and the Zoo Map and Rule Shift Card tests of the Behavioral Assessment of the Dysexecutive Syndrome. A cut-off of 17 optimally differentiated patients from controls. While 88% of the IFS sub-tests discriminated patients from controls, only 67% of the FAB sub-tests did so. Conclusion: Age and education should be taken into account when

interpreting performance on the IFS. The IFS is useful to detect executive dysfunction in DZNeP research buy AD, showing good discriminant and concurrent validities.”
“Background: Sequential hip fractures are associated with increased morbidity and mortality. Understanding of risk factors is important for secondary prevention. Although hip fractures have a multifactorial aetiology related to falls, it is unknown whether fracture management approach influences the risk of sequential hip fractures. Objectives: Our objective is to explore whether subsequent contralateral hip fractures are more common following femoral head replacement or salvage procedures for the treatment of hip fractures. Methods: Patients older than 50, admitted to a single regional trauma unit in Worcestershire between 2010 and 2012 were identified from the national database. 700 patients matched our inclusion criteria and case notes were reviewed. The male to female ratio was 1:3.3 and the mean age was 82.8 years (standard deviation: 8.9 years). Contralateral fractures were identified from admission X-rays. Risk factors were analysed based on patient demographics and data related to first hip fracture management.

In this article, we discuss the management of SDB in pediatric pa

In this article, we discuss the management of SDB in pediatric patients, which relies on the accurate assessment of symptoms of SDB, identification of comorbidities known to increase the severity of SDB, and appropriate preoperative assessment of the patient. The approach to patients with snoring and other signs of sleep-disordered breathing (SDB) GSK690693 mw represents a common management challenge for the pediatrician, pulmonologist, anesthesiologist, and otolaryngologist. From the assessment of the historical symptoms of SDB to the consideration of comorbid conditions and the evaluation for potential anatomic sources for obstruction, the evaluation of patients with SDB

can be complex and confusing, with the decision for and timing of subsequent intervention(s) unclear. The American Academy of Otolaryngology-Head and Neck Surgery published “Clinical Practice Guideline: Polysomnography for Sleep-Disordered Breathing Prior to Tonsillectomy in Children” in 2011 to elucidate the approach to this patient population. 1 In the production of this clinical practice guideline (CPG), a panel of experts from the fields of anesthesiology, otolaryngology-head and neck surgery,

pediatrics, pulmonology, and sleep medicine was assembled to review the indications for and proper use of polysomnography (PSG) in the management of children with SDB. Their recommendations, which will be discussed in detail, are outlined in Table 1. [Graphics] .”
“Although LY2157299 it has been suggested that switching of factor VIII (FVIII) products

may increase inhibitor formation this is disputed. Half of UK patients changed rFVIII Selonsertib cell line brands because of national contracting in 2010, presenting an opportunity to compare inhibitor incidence of switchers with non-switchers. Centres were requested to test all the patients for inhibitors prior to the switching date and 6-monthly thereafter. Positive and negative inhibitor test data were also collected to analyse for testing bias. A total of 1198 patients with severe haemophilia A and treated with Advate, Kogenate/Helixate or Refacto AF preswitch were included in the analysis, of whom 516 switched to Refacto-AF and 682 did not switch products. Five new inhibitors were reported amongst previously treated patients ( bigger than 50 exposure days) with a median titre at the time of detection of 1.25BUmL(-1) (IQR 0.7-23.05). One inhibitor occurred in a non-switcher using Kogenate, an incidence of 1.5 per 1000 treatment-years (95% CI 0.2-10.5). Four inhibitors arose in patients who had switched from Kogenate (two) or Advate (two) to ReFacto-AF, an incidence of 7.8 per 1000 treatment-years (95% CI 2.9-20.8). These incidence rates did not differ significantly from one another (incidence rate ratio 5.3 (95% CI 0.5-260.3) or from the historical rate of 6.05 inhibitors/1000 treatment-years (95% CI 5.18-7.06). Only one inhibitor (non-switcher) persisted. Non-switchers were significantly older (P= 0.

In this review, we summarize the data available regarding antigen

In this review, we summarize the data available regarding antigen targeting to APC receptors in cattle, sheep and pig and discuss the results found in these animals in the context of what has been obtained in mice. (C) 2013 Elsevier Ltd. All rights reserved.”
“In recent years there

has been considerable concern that certain classes of drugs, 3-deazaneplanocin A in vivo for example antidepressants, may increase the risk of suicide. In this current opinion article, we examine the literature on methodological and statistical approaches to the design and analysis of suicidal event studies. Experimental, ecological and observational studies of the relationship between drugs and suicidal events (thoughts, attempts and completion) are discussed. Areas considered include analysis of spontaneous reporting system data, ecological trends in national and/or small area (e.g. county) suicide rates, metaanalyses of randomized clinical trials, and large-scale medical claims data. New statistical and experimental strategies for investigating

possible associations between drugs and suicide are highlighted, and we suggest directions for future statistical/methodological research. To put this into context, we then review the most recent literature on the relationship between drugs (antidepressants, antiepileptics, varenicline, montelukast and antipsychotics) and suicidal events.\n\nOverall, there appears to be little evidence that drugs increase the risk of suicide and related selleck kinase inhibitor behaviour. Numerous lines of evidence Selleckchem Bcl-2 inhibitor in adults clearly demonstrate that inadequate treatment of depression (pharmacotherapy and/or psychotherapy) is associated with increased risk of suicidal behaviour. In children, the results are less clear and further study is required to better delineate which children benefit from treatment and who may be at increased risk as a consequence of treatment. From a statistical and methodological perspective, the field of pharmacoepidemiology is a fertile area for statistical research, both in theory and in application. In general, methods have been adopted from other areas such as general epidemiology, despite the singular

nature of many of the problems that are unique to drug safety in general, in particular the study of rare events. Finally, there is considerable debate concerning the communication of risk. For suicide, regulatory action has been taken largely on the basis of evidence suggesting increased risk of suicidal thoughts. However, suicidal thoughts are quite common, particularly among patients with depression, and may have little relationship to suicidal behaviour and/or completion.”
“Owing to rarity and awareness deficiency towards inflammatory myofibroblastic tumor (IMT), we sought to review on its clinicopathological features; arising awareness to achieve early diagnosis; exploring prognostic factors and then establishing a treatment protocol.

“This clinical article reports a technique, apicotomy, for

“This clinical article reports a technique, apicotomy, for managing dilacerated or ankylosed canines. The records of 3 patients successfully treated with apicotomy are presented. Orthodontists observe clinically significant incidences

of impacted maxillary selleck chemical canines in their daily practices. Several procedures have been described to bring an ankylosed, impacted tooth into occlusion. Luxation is the most widely used solution, but there are risks involved with that approach, and the success rate is low. Surgical repositioning has also been used, but morbidity is high, and the aggressiveness of the procedure might also contraindicate it. Ankylosis might be related to the anatomic position of the canine’s root apex and its adjacent anatomic structures. Apicotomy is a guided fracture of a canine root apex, followed by its orthodontic traction. It is a conservative surgical alternative for treating impacted canines with dilacerations or apical root ankylosis.”
“Smart biomaterials play a key role when aiming at successful

tissue repair by means of regenerative Copanlisib mw medicine approaches, and are expected to contain chemical as well as mechanical cues that will guide the regenerative process. Recent advances in the understanding of stem cell biology and mechanosensing have shed new light onto the importance of the local microenvironment in determining cell fate. Herein we report the biological properties of a bioactive, biodegradable calcium phosphate glass/polylactic acid composite biomaterial that promotes bone marrow-derived endothelial progenitor cell (EPC) mobilisation, differentiation and angiogenesis through the creation of a controlled bone healing-like

microenvironment. The angiogenic response is triggered by biochemical and mechanical AZD9291 cues provided by the composite, which activate two synergistic cell signalling pathways: a biochemical one mediated by the calcium-sensing receptor and a mechanosensitive one regulated by non-muscle myosin II contraction. Together, these signals promote a synergistic response by activating EPCs-mediated VEGF and VEGFR-2 synthesis, which in turn promote progenitor cell homing, differentiation and tubulogenesis. These findings highlight the importance of controlling microenvironmental cues for stem/progenitor cell tissue engineering and offer exciting new therapeutical opportunities for biomaterialbased vascularisation approaches and clinical applications.”
“Eukaryotic DNA replication is preceded by the assembly of prereplication complexes (pre-RCs) at or very near origins in G1 phase, which licenses origin firing in S phase. The archaeal DNA replication machinery broadly resembles the eukaryal apparatus, though simpler in form. The eukaryotic replication initiator origin recognition complex (ORC), which serially recruits Cdc6 and other pre-RC proteins, comprises six components, Orc1-6.

We found that GE confers a potent neuroprotective agent against M

We found that GE confers a potent neuroprotective agent against MPTP-induced dopaminergic denervation and may become a potential therapeutic agent for PD and/or its progression.”
“Purpose Downstaging (DS) of rectal cancers is achieved in approximately 45% of patients with neoadjuvant fluorouracil (FU) -based chemoradiotherapy (CRT). Polymorphisms in the thymidylate synthase gene (TYMS) had previously defined two risk groups associated with disparate tumor 10058-F4 DS rates (60% v 22%). We conducted a prospective single-institution phase II study using TYMS genotyping to direct neoadjuvant

CRT for patients with rectal cancer.\n\nPatients and Methods Patients with T3/T4, N0-2, M0-1 rectal adenocarcinoma were evaluated for germline TYMS genotyping. Patients with TYMS *2/*2, *2/*3, or *2/*4 (good risk) were treated with standard chemoradiotherapy using infusional FU at 225 mg/m(2)/d. Patients with TYMS *3/*3 or *3/*4 (poor risk) were treated with FU/RT plus weekly intravenous irinotecan at 50 mg/m(2). The primary end point was pathologic DS. Secondary end points included complete tumor response (ypT0), toxicity, recurrence rates, and overall survival.\n\nResults Overall, 135 patients were enrolled, of whom 27.4% (37 of 135) were considered poor risk. The prespecified statistical goals were URMC-099 concentration achieved, with DS and ypT0 rates reaching 64.4% and 20%

for good-risk and 64.5% and 42% for poor-risk patients, respectively.\n\nConclusion To our knowledge, this is the first study to prospectively use TYMS genotyping to direct neoadjuvant CRT in patients with rectal cancer. High rates of DS and ypT0 were achieved among both risk groups when personalized treatment was based on TYMS genotype. These results are encouraging, and further evaluation of this genotype-based strategy Epacadostat cost using a randomized study design for locally advanced rectal cancer is warranted. J Clin Oncol 29: 875-883. (C) 2011 by American Society of Clinical Oncology”
“Regulatory approvals for deliberate release of GM maize events into the environment have lead to real situations of coexistence between GM and non-GM, with some fields being cultivated with

GM and conventional varieties in successive seasons. Given the common presence of volunteer plants in maize fields in temperate areas, we investigated the real impact of GM volunteers on the yield of 12 non-GM agricultural fields. Volunteer density varied from residual to around 10% of plants in the field and was largely reduced using certain cultural practices. Plant vigour was low, they rarely had cobs and produced pollen that cross-fertilized neighbour plants only at low-but variable-levels. In the worst-case scenario, the estimated content of GMO was 0.16%. The influence of GM volunteers was not enough to reach the 0.9% adventitious GM threshold but it could potentially contribute to adventitious GM levels, especially at high initial densities (i.e.