Mismatch Hypothesis Research Articles

(A bit) Earlier or later is always better: Phenological shifts in consumer–resource interactions

Phenology is a crucial life history trait for species interactions and it can have great repercussions on the persistence of communities and ecosystems. Changes in phenology caused by climate change can disrupt species interactions causing decreases in consumer growth rates, as suggested by the match–mismatch hypothesis (MMH). However, it is still not clear what the long-term consequences of such phenological changes are. In this paper, we present models in which phenology and consumer–resource feedbacks determine long-term community dynamics. Our results show that consumer viability is constrained by limits in the amount of phenological mismatch with their resources, in accordance with the MMH, but the effects of phenological shifts are often nonmonotonic. Consumers generally have higher abundances when they recruit some time before or after their resources because this reduces the long-term effects of overexploitation that would otherwise occur under closer synchrony. Changes in the duration of recruitment phenologies also have important impacts on community stability, with shorter phenologies promoting oscillations and cycles. For small community modules, the effects of phenological shifts on populations can be explained, to a great extent, as superpositions of their effects on consumer–resource pairs. We highlight that consumer–resource feedbacks and overexploitation, which are not typically considered in phenological models, are important factors shaping the long-term responses to phenological changes caused by climate change.

Effects of climate change on European ducks: what do we know and what do we need to know?

The consequences of climate change for bird populations have received much attention in recent decades, especially amongst cavity‐nesting songbirds, yet little has been written on ducks (Anatidae) despite these being major elements of wetland diversity and important quarry species. This paper reviews the major known consequences of climate change for birds in general, and relates these to the limited information available specifically for ducks. Climate change can influence migration distance and phenology, potentially affecting patterns of mortality, as well as distribution and reproductive success in ducks. Studies addressing effects of climate change are, however, restricted to very few duck species, including mallardAnas platyrhynchosand common eiderSomateria mollissima. Shifts in winter duck distributions have been observed, whereas the mismatch hypothesis (mistiming between the periods of peak energy requirements for young and the peak of seasonal food availability) has received limited support with regard to ducks. We propose a range of monitoring initiatives, including population surveys, breeding success monitoring schemes and individual duck marking, which should later be integrated through population modelling and adaptive management to fill these gaps.

Mismatch and the Paternalistic Justification for Selective College Admissions

Although some scholars report that all students are better served by attending more prestigious postsecondary institutions, others have argued that students are better off attending colleges where they are about average in terms of academic ability and suffer worse outcomes if they attend schools that are “out of their league” at which they are “overmatched.” The latter argument is most frequently deployed as a paternalistic justification for ending affirmative action. We take advantage of a natural admissions experiment at the University of California to test the effect of being overmatched for students on the margin of admission to elite universities. Consistent with the mismatch hypothesis, we find that students accumulate more credits when they attend less demanding institutions. However, students do not earn higher grades and are no more or less likely to drop out of schools where they are overmatched and are less likely to drop out than they would have been had they attended less demanding institutions.

Relationships of interannual variability in SST and phytoplankton blooms with giant jellyfish (Nemopilema nomurai) outbreaks in the Yellow Sea and East China Sea

Giant jellyfish (Nemopilema nomurai) outbreaks in relation to satellite sea surface temperature (SST) and chlorophyll-a concentrations (Chl-a) were investigated in the Yellow Sea and East China Sea (YECS) from 1998 to 2010. Temperature, eutrophication, and match–mismatch hypotheses were examined to explain long-term increases and recent reductions of N. nomurai outbreaks. We focused on the timing of SST reaching 15 °C, a critical temperature enabling polyps to induce strobilation and enabling released ephyra to grow. We analyzed the relationship of the timing with interannual variability of SST, Chl-a, and the timing of phytoplankton blooms. Different environmental characteristics among pre-jellyfish years (1998–2001), jellyfish years (2002–2007, 2009), and non-jellyfish years (2008, 2010) were assessed on this basis. The SST during late spring and early summer increased significantly from 1985 to 2007. This indicated that high SST is beneficial to the long-term increases in jellyfish outbreaks. SST was significantly lower in non-jellyfish years than in jellyfish years, suggesting that low SST might reduce the proliferation of N. nomurai. We identified three (winter, spring, and summer) major phytoplankton bloom regions and one summer decline region. Both Chl-a during non-blooming periods and the peak increased significantly from 1998 to 2010 in most of the YECS. This result indicates that eutrophication is beneficial to the long-term increases in jellyfish outbreaks. Timing of phytoplankton blooms varied interannually and spatially, and their match and mismatch to the timing of SST reaching 15 °C did not correspond to long-term increases in N. nomurai outbreaks and the recent absence.

The interaction between child maltreatment, adult stressful life events and the 5-HTTLPR in major depression

Both childhood maltreatment and adult stressful life events are established risk factors for the onset of depression in adulthood. However, the interaction between them can be viewed through two conflicting frameworks. Under a mismatch hypothesis stressful childhoods allow ‘adaptive programming’ for a stressful adulthood and so can be protective. Only when childhood and adulthood do not match is there a risk of behavioural problems. Alternatively, under the cumulative stress hypothesis we expect increased risk with each additional stressor. It has also been suggested that an individual's genetic background may determine the extent they undergo adaptive programming, and so which of these two hypotheses is relevant. In this study we test for an interaction between exposure to childhood maltreatment and adult stressful life events in a retrospective sample of 455 individuals, using major depression as the outcome. We also test whether this interaction differs by genotype at the 5-HTTLPR, a candidate for an individual's plasticity to adaptive programming.Early maltreatment and stressful life events in adulthood interacted to produce increased risk for depression over each individually (p = 0.055). This supports the cumulative stress hypothesis over the mismatch hypothesis, at least with respect to severe environmental risk factors. This effect was not altered by 5-HTTLPR allele, suggesting there was no difference by genotype in adaptive programming to these events. We suggest that the apparent additional vulnerability to stressful events of those who have experienced maltreatment has clinical relevance, highlighting the importance of providing support beyond the immediate aftermath of maltreatment into adulthood.

Do Racial Preferences Affect Minority Learning in Law Schools?

An analysis of the The Bar Passage Study (BPS) reveals that minorities are both less likely to graduate from law school and less likely to pass the bar compared to whites even after adjustments are made for group differences in academic credentials. To account for these adjusted racial gaps in performance, some researchers put forward the “mismatch hypothesis,” which proposes that students learn less when placed in learning environments where their academic skills are much lower than the typical student. This article presents new results from the BPS that account for both measurement‐error bias and selection‐on‐unobservables bias that makes it more difficult to find a mismatch effect if in fact one exists. I find much more evidence for mismatch effects than previous research and report magnitudes from mismatch effects more than sufficient to explain racial gaps in performance.

P.2.019 The mismatch hypothesis: a new way of linking early experiences and adult environment to vulnerability to stress

Purpose of the study: Chronic stress is considered one of the main risk factors for depression. Interestingly, not all individuals develop psychopathology after chronic stress. In contrast to the prevailing view that stress effects are cumulative and increase stress vulnerability later in life, the recently formulated mismatch hypothesis proposes that individuals experiencing high levels of psychosocial stress early in life are programmed for dealing with high psychosocial stress and are therefore resilient to high stress levels in later life [1]. We here test this hypothesis by comparing the developmental effects of two different early life conditions, when tested under two opposite adult environments. Methods used: We used female BALB/c mice that underwent either adverse early life conditions (limited nesting material) or a supportive environment (early handling) from PND2 to PND9. At weaning, the animals of each group were assigned to either group housing (supportive environment) or single housing (social deprivation, adverse environment). At adulthood, we compared the molecular and the behavioural effects of the interaction between early and adult environment, in particular on anxiety like and depressive like behaviour.

Adolescent social stress does not necessarily lead to a compromised adaptive capacity during adulthood: A study on the consequences of social stress in rats

Childhood bullying or social stress in adolescent humans is generally considered to increase the risk of developing behavioral disorders like depression in adulthood. Juveniles are hypothesized to be particularly sensitive to stressors in their environment due to the relatively late maturation of brain areas that are targeted by stress such as the prefrontal cortex and hippocampus. In our study male adolescent rats were subjected to repeated social defeat on postnatal day (PND) 28, 31 and 34 (experiment 1) or to daily social defeats between PND 35 and 42 (experiment 2). Adolescent rats in experiment 1 were socially housed in pairs with a male of similar age during and after the social defeat. In experiment 2 adolescents were housed either alone or with an age-mate for 7days (PND 35–42) next to either a highly aggressive or a non-aggressive adult male neighbor with whom a repeated physical interaction was allowed. In experiment 1 the adolescent defeats affected subsequent play behavior with the cage mate. Socially stressed rats more frequently initiated play behavior but also adopted more frequently submissive postures during the play fights. As adults, they seemed to cope behaviorally and physiologically better with a similar exposure to a residential aggressive male rat than unstressed controls. In experiment 2 acute effects of adolescent social stress were studied on neuroplasticity markers like hippocampal cell proliferation and neurogenesis as well as hippocampal brain-derived neurotrophic factor (BDNF) levels. The 2nd experiment also studied long-term effects of the adolescent stress in the response to an adult social defeat. A few acute but minor changes in brain plasticity markers and behavior were observed but these were transient and no behavioral or physiological effects persisted into adulthood. The results from both experiments support the theory developed in the so-called “match–mismatch hypothesis” which claims that the final consequence of childhood adversity depends on how well the early life environment matches the challenges in later life. Socially stressed adolescents are rather resilient to the lasting behavioral and physiological effects of the stress exposure if they are socially housed afterward and have the ability to recover.

Mismatch revisited: what is trophic mismatching from the perspective of the plankton?

Long-term changes in the seasonal timing of phytoplankton and zooplankton population development (i.e. phenological changes) have been widely reported in freshwater and marine ecosystems, and have been interpreted as a biological response to ongoing climate change. Observed among-species variations in the rates and patterns of these changes have led to concerns that seasonal trophic interactions may become de-synchronized in plankton communities, following the logic of the match– mismatch hypothesis. Herein, the current evidence for long-term mismatching within plankton communities is evaluated and the meaning of this concept for the plankton is explored. Despite the large number of studies documenting phenological change in plankton communities, very few explicitly quantify mismatching among trophic levels within the same study system, and quantify its ecological impacts. There is a clear need to build the evidence base for the mismatching phenomenon. In this endeavour, we must carefully define the seasonality of resource availability based on prior ecological knowledge, and embrace the challenges posed by organisms with more complex life cycles and the ecological network context within which plankton interact. In addition, we must acknowledge that, while mismatching in the plankton and in non-planktonic systems relates to synchrony between resource supply and consumer demand, there are conceptual differences in the phenomenon between these two broad classes of systems. For planktonic systems, mismatching is best visualized as an alteration of the rates and lags of the interaction between dynamically linked consumers and resources, rather than simple and independent phase shifts of seasonal abundance peaks at each trophic level.

Cross-sectional determinants of bank performance under deposit dollarization in emerging markets

Dollar-denominated deposits and loans could increase financial fragility in emerging market banking systems. This currency mismatch does not only increase banks' currency risk when the proportion of dollar-denominated loans with respect to local-denominated loans increases but also it increases their clients' default risk if depreciation occurs. This paper investigates the profitability of 36 dollarized banking systems. Results suggest that after controlling for some macroeconomic and institutional variables, dollarization, as the currency mismatch hypothesis suggests, depresses bank performance and lowers bank profitability. Results also show that the effect of institutions more than offsets the negative impact of dollarization on banks' profitability.

New literacies as multiply placed practices: expanding perspectives on young people's literacies across home and school

The home–school mismatch hypothesis has played an important part in sociocultural studies of literacy and schooling since the 1970s. In this paper, we explore how this now classic literacy thesis has developed a new life in studies of digital media and electronic communications with regards to young people and schools, what we call the new home–school mismatch hypothesis or new literacy thesis. We report on two studies, one conducted in Australia and the other in Greece, that worked with 14–16-year-old young people to explore the relationships between their use of digital media in- and out-of-school. Our analysis suggests that the relationship between literacy and digital media use in and outside of school is more complex than is often presented in media commentary and in research and points to the need for more careful consideration of the relationship between school and out-of-school practice and knowledge.

Refinement of the Magnetic Resonance Diffusion-Perfusion Mismatch Concept for Thrombolytic Patient Selection

The DIAS-2 study was the only large, randomized, intravenous, thrombolytic trial that selected patients based on the presence of ischemic penumbra. However, DIAS-2 did not confirm the positive findings of the smaller DEDAS and DIAS trials, which also used penumbral selection. Therefore, a reevaluation of the penumbra selection strategy is warranted. In post hoc analyses we assessed the relationships of magnetic resonance imaging-measured lesion volumes with clinical measures in DIAS-2, and the relationships of the presence and size of the diffusion-perfusion mismatch with the clinical effect of desmoteplase in DIAS-2 and in pooled data from DIAS, DEDAS, and DIAS-2. In DIAS-2, lesion volumes correlated with National Institutes of Health Stroke Scale (NIHSS) at both baseline and final time points (P<0.0001), and lesion growth was inversely related to good clinical outcome (P=0.004). In the pooled analysis, desmoteplase was associated with 47% clinical response rate (n=143) vs 34% in placebo (n=73; P=0.08). For both the pooled sample and for DIAS-2, increasing the minimum baseline mismatch volume (MMV) for inclusion increased the desmoteplase effect size. The odds ratio for good clinical response between desmoteplase and placebo treatment was 2.83 (95% confidence interval, 1.16-6.94; P=0.023) for MMV >60 mL. Increasing the minimum NIHSS score for inclusion did not affect treatment effect size. Pooled across all desmoteplase trials, desmoteplase appears beneficial in patients with large MMV and ineffective in patients with small MMV. These results support a modified diffusion-perfusion mismatch hypothesis for patient selection in later time-window thrombolytic trials. Clinical Trial Registration- URL: http://www.clinicaltrials.gov. Unique Identifiers: NCT00638781, NCT00638248, NCT00111852.

Early nutrition programming of long-term health

Increasing evidence from the EU Project EARNEST and many other investigators demonstrates that early nutrition and lifestyle have long-term effects on later health and the risk of common non-communicable diseases (known as 'developmental programming'). Because of the increasing public health importance and the transgenerational nature of the problem, obesity and associated disorders are the focus of the new EU funded project 'EarlyNutrition'. Currently, three key hypotheses have been defined: the fuel mediated 'in utero' hypothesis suggests that intrauterine exposure to an excess of fuels, most notably glucose, causes permanent changes of the fetus that lead to obesity in postnatal life; the accelerated postnatal weight gain hypothesis proposes an association between rapid weight gain in infancy and an increased risk of later obesity and adverse outcomes; and the mismatch hypothesis suggests that experiencing a developmental 'mismatch' between a sub-optimal perinatal and an obesogenic childhood environment is related to a particular predisposition to obesity and corresponding co-morbidities. Using existing cohort studies, ongoing and novel intervention studies and a basic science programme to investigate those key hypotheses, project EarlyNutrition will provide the scientific foundations for evidence-based recommendations for optimal nutrition considering long-term health outcomes, with a focus on obesity and related disorders. Scientific and technical expertise in placental biology, epigenetics and metabolomics will provide understanding at the cellular and molecular level of the relationships between early life nutritional status and the risk of later adiposity. This will help refine strategies for intervention in early life to prevent obesity.

Abstract 2600: Refinement of the MR Diffusion-perfusion Mismatch Concept for Thrombolytic Patient Selection: Insights from the Desmoteplase In Acute Stroke Trials

The DIAS-2 study was the only large, randomized intravenous thrombolytic trial that selected patients based on the presence of ischemic penumbra. However, DIAS-2 did not confirm the positive findings of the smaller DEDAS and DIAS trials, which also used penumbral selection. Therefore a reevaluation of the penumbra selection strategy is warranted. In post-hoc analyses we assessed the relationships of MRI-measured lesion volumes to clinical measures in DIAS-2, and the relationships of the presence and size of the diffusion-perfusion mismatch to the clinical effect of desmoteplase in DIAS-2 (MRI-selected patients) and in pooled data from MRI-selected 90- and 125-μg/kg dose groups in DIAS, DEDAS, and DIAS-2. In DIAS-2, lesion volumes correlated with NIHSS at both baseline and final time points (P&lt;0·0001), and lesion growth was inversely related to good clinical outcome (P=0.004). In the pooled analysis, treatment was associated with 47% clinical response rate in desmoteplase (n=143) versus 34% in placebo (n=73; P=0.08). For both the pooled sample and for DIAS-2, increasing the minimum baseline mismatch volume (MMV) for inclusion increased the desmoteplase effect size, preferentially decreasing the placebo-response rate. There was a trend of statistically significant differences in effect size in ≤60 mL versus &gt;60 mL baseline mismatch subgroups (P=0.083). The odds ratio for good clinical response between desmoteplase and placebo treatment was 2.83 (95% CI, 1.16-6.94, P=0.023) for a MMV &gt;60 mL. Increasing the minimum NIHSS for inclusion did not affect treatment effect size. Pooled across all desmoteplase trials, penumbral selection by MRI diffusion-perfusion mismatch favored desmoteplase clinical benefit, especially for larger MMV. Based on these results, a three-fold reduction in future trial sample size requirements would be achieved using a criterion of baseline MMV &gt;60 mL over any visible mismatch. These results support a modified diffusion-perfusion mismatch hypothesis for patient selection in later-time-window thrombolytic trials.

Testing the cumulative stress and mismatch hypotheses of psychopathology in a rat model of early-life adversity

BackgroundIn the present study, we tested both the cumulative stress and the mismatch hypothesis of psychopathology. For this purpose the combined effects of early-life adversity and later-life stress exposure on behavioral markers of psychosis susceptibility were studied in male Wistar rats. MethodExperiment I: rat pups divided on the basis of the levels of their maternal care experience in low, medium or high maternal care groups, were reared post-weaning in groups (Exp. IA) or in social isolation (Exp. IB) and tested at adulthood under basal conditions or after an acute corticosterone (CORT) administration. Maternal care levels were assessed by measuring the dam's licking and grooming (LG) the first postnatal week of life.Experiment II: rat pups exposed as neonates to daily sessions of 8h of maternal separation (MS) on postnatal days 3, 4 and 5 either altogether in their home cage (HOME SEP) or alone in a novel environment (NOVEL SEP), were reared post-weaning in groups and tested at adulthood under basal conditions.Adult testing included behaviors marking psychosis susceptibility: apomorphine-induced gnawing (APO-gnawing), acoustic startle response and its modulation by a prepulse stimulus (PPI). The behavior of the Medium LG offspring was used as baseline reference for all the three experiments. ResultsExperiment I: Low maternal LG history alone had limited effects on the behavior of Wistar offspring, although increased acoustic startle and increased PPI, at high prepulse intensity levels, were observed. When low maternal LG history was combined with post-weaning social isolation, basal APO-gnawing was decreased and PPI increased, compared to High LG and Med LG offspring. This reflects attenuated psychosis susceptibility. High LG offspring reared in isolation displayed, however, the highest APO-gnawing and the lowest PPI levels among rats reared in social isolation, which is indicative for increased psychosis susceptibility. These findings support the mismatch hypothesis. For demonstration of the cumulative stress hypothesis an injection of CORT in the adult Low LG offspring was required that increased APO-gnawing and reduced PPI. This CORT-induced PPI disruption was greatly enhanced after additional isolation rearing. The High LG group, either socially housed or reared in isolation, was resistant to the acute effects of CORT at adulthood.Experiment II: MS increased psychosis susceptibility only in NOVEL SEP rats that had experienced MS in the context of early social isolation. These individuals displayed increased adult APO-gnawing and reduced PPI, if reared post-weaning in a condition that does not match with their early life social environment (i.e. group housing). This finding supports the mismatch hypothesis. ConclusionThe outcome of environmental manipulations on developmental programming of psychosis susceptibility depends on the interplay of early-life adversity and later-life stressors in a manner that supports the mismatch hypothesis. However, evidence for the cumulative stress hypothesis arises if vulnerable individuals are exposed in later life additionally to excess of the stress hormone CORT.

Pharmacokinetic Mismatch Does Not Lead to Emergence of Isoniazid- or Rifampin-Resistant Mycobacterium tuberculosis but to Better Antimicrobial Effect: a New Paradigm for Antituberculosis Drug Scheduling

Multidrug resistant-tuberculosis is a pressing problem. One of the major mechanisms proposed to lead to the emergence of drug resistance is pharmacokinetic mismatch. Stated as a falsifiable hypothesis, the greater the pharmacokinetic mismatch between rifampin and isoniazid, the higher the isoniazid- and rifampin-resistant subpopulation sizes become with time. To test this, we performed hollow-fiber-system studies for both bactericidal and sterilizing effects in experiments of up to 42 days. We mimicked pharmacokinetics of 600-mg/day rifampin and 300-mg/day isoniazid administered to patients. Rifampin was administered first, followed by isoniazid 0, 6, 12, and 24 h later. The treatment was for drug-susceptible Mycobacterium tuberculosis in some experiments and hollow fiber systems with inoculum preseeded with isoniazid- and rifampin-resistant isogenic Mycobacterium tuberculosis strains in others. Analysis of variance revealed that the 12-h and 24-h-mismatched regimens always killed better than the matched regimens during both bactericidal and sterilizing effects (P < 0.05). This means that either the order of scheduling or the sequential administration of drugs in combination therapy may lead to significant improvement in microbial killing. Rifampin-resistant and isoniazid-resistant subpopulations were not significantly higher with increased mismatching in numerous analysis-of-variance comparisons. Thus, the pharmacokinetic mismatch hypothesis was rejected. Instead, sequential administration of anti-tuberculosis (TB) drugs (i.e., deliberate mismatch) following particular schedules suggests a new paradigm for accelerating M. tuberculosis killing. We conclude that current efforts aimed at better pharmacokinetic matching to decrease M. tuberculosis resistance emergence are likely futile and counterproductive.

Beach characteristics mitigate effects of onshore wind on horseshoe crab spawning: implications for matching with shorebird migration in Delaware Bay

Disruption of food availability by unfavorable physical processes at energetically demanding times can limit recruitment of migratory species as predicted by the match–mismatch hypothesis. Identification and protection of disruption-resistant habitat could contribute to system resilience. For example, horseshoe crab Limulus polyphemus spawning and shorebird stopover must match temporally in Delaware Bay for eggs to be available to shorebirds. Onshore winds that generate waves can create a mismatch by delaying horseshoe crab spawning. We examined effects of beach characteristics and onshore winds on spawning activity at five beaches when water temperatures were otherwise consistent with early spawning activity. Onshore winds resulted in reduced spawning activity during the shorebird stopover, when spawning typically peaks in late May. During the period with high onshore wind, egg density was highest on the foreshore exposed to the lowest wave heights. Onshore wind was low in early June, and spawning and egg densities were high at all sites, but shorebirds had departed. Beaches that can serve as a refuge from wind and waves can be identified by physical characteristics and orientation to prevailing winds and should receive special conservation status, especially in light of predicted increases in climate change-induced storm frequency. These results point to a potential conservation strategy that includes coastal management for adapting to climate change-induced mismatch of migrations.

A test of the mismatch hypothesis: How is timing of reproduction related to food abundance in an aerial insectivore?

In seasonal environments, vertebrates are generally thought to time their reproduction so offspring are raised during the peak of food abundance. The mismatch hypothesis predicts that reproductive success is maximized when animals synchronize their reproduction with the food supply. Understanding the mechanisms influencing the timing of reproduction has taken on new urgency as climate change is altering environmental conditions during reproduction, and there is concern that species will not be able to synchronize their reproduction with changing food supplies. Using data from five sites over 24 years (37 site-years), we tested the assumptions of the mismatch hypothesis in the Tree Swallow (Tachycineta bicolor), a widespread aerial insectivore, whose timing of egg-laying has shifted earlier by nine days since the 1950s. Contrary to the mismatch hypothesis, the start of egg-laying was strongly related to food abundance (flying insect biomass) during the laying period and not to timing of the seasonal peak in food supply. In fact, food abundance generally continued to increase throughout the breeding season, and there was no evidence of selection based on the mistiming of laying with the seasonal peak of food abundance. In contrast, there was selection for laying earlier, because birds that lay earlier generally have larger clutches and fledge more young. Overall, initial reproductive decisions in this insectivore appear to be based on the food supply during egg formation and not the nestling period. Thus, the mismatch hypothesis may not apply in environments with relatively constant or abundant food throughout the breeding season. Although climate change is often associated with earlier reproduction, our results caution that it is not necessarily driven by selection for synchronized reproduction.

Beyond the Inner City

In this study the job accessibility of low-income job seekers was compared with that of the affluent majority in a polycentric urban structure. Kain's spatial mismatch hypothesis was extended not only to examine where and why low-income job seekers have lower job accessibility than high-income job seekers but also to compare changes from 1990 to 2000 in the Los Angeles, California, metropolitan area. The job accessibility measure applied in this research captured travel impedance and both job supply and demand. The results suggested that spatial mismatch still existed and that it continued to increase over time. However, the spatial pattern of mismatch had changed. Low-income job seekers were more disadvantaged in the inner-ring suburbs, mainly because of the lag in the residential suburbanization of low-income job seekers. This research contributed to the understanding of the extent and consequences of urban spatial transformation and suggested that social equity problems be addressed from a broader spatial perspective.

An experimental examination of temperature interactions in the match–mismatch hypothesis for Pacific cod larvae

The match–mismatch hypothesis (MMH) predicts that marine fish larvae will have their highest rate of growth and survival when they overlap with their prey. However, Pacific cod ( Gadus macrocephalus ) and other gadids continue to thrive in the Bering Sea despite delayed prey production resulting from warming and loss of sea ice. In this study, we examined how temperature mediates growth and survival of Pacific cod larvae under varying match–mismatch conditions. Cod larvae were reared at two temperatures (3 °C and 8 °C) and exposed to one of five different food treatments over a 6-week period: (i) high food (HF) (match); (ii) low food (LF); (iii) HF then LF (HF–LF); and (iv) LF then HF (LF–HF) (2–4 mismatch); and (v) no food (NF) (complete mismatch). Results showed that cold environments allow Pacific cod larvae to bridge gaps in prey availability (i.e., timing and magnitude), but negatively impact survival over longer periods. Under warmer conditions, mismatches in prey significantly impacted growth and survival. However, both yolk reserves and compensatory growth mechanisms reduced the severity of mismatches occurring in the first 3 weeks of development. Our results demonstrate a clear need to incorporate the direct effects of temperature on fish larvae in food limitation models.