Statistical Mechanics of High-Dimensional Inference

To model modern large-scale datasets, we need efficient algorithms to infer a set of $P$ unknown model parameters from $N$ noisy measurements. What are fundamental limits on the accuracy of parameter inference, given finite signal-to-noise ratios, limited measurements, prior information, and computational tractability requirements? How can we combine prior information with measurements to achieve these limits? Classical statistics gives incisive answers to these questions as the measurement density $\alpha = \frac{N}{P}\rightarrow \infty$. However, these classical results are not relevant to modern high-dimensional inference problems, which instead occur at finite $\alpha$. We formulate and analyze high-dimensional inference as a problem in the statistical physics of quenched disorder. Our analysis uncovers fundamental limits on the accuracy of inference in high dimensions, and reveals that widely cherished inference algorithms like maximum likelihood (ML) and maximum-a posteriori (MAP) inference cannot achieve these limits. We further find optimal, computationally tractable algorithms that can achieve these limits. Intriguingly, in high dimensions, these optimal algorithms become computationally simpler than MAP and ML, while still outperforming them. For example, such optimal algorithms can lead to as much as a 20% reduction in the amount of data to achieve the same performance relative to MAP. Moreover, our analysis reveals simple relations between optimal high dimensional inference and low dimensional scalar Bayesian inference, insights into the nature of generalization and predictive power in high dimensions, information theoretic limits on compressed sensing, phase transitions in quadratic inference, and connections to central mathematical objects in convex optimization theory and random matrix theory.Comment: See http://ganguli-gang.stanford.edu/pdf/HighDimInf.Supp.pdf for supplementary materia

Mostly Harmless Simulations? Using Monte Carlo Studies for Estimator Selection

We consider two recent suggestions for how to perform an empirically motivated Monte Carlo study to help select a treatment effect estimator under unconfoundedness. We show theoretically that neither is likely to be informative except under restrictive conditions that are unlikely to be satisfied in many contexts. To test empirical relevance, we also apply the approaches to a real-world setting where estimator performance is known. Both approaches are worse than random at selecting estimators which minimise absolute bias. They are better when selecting estimators that minimise mean squared error. However, using a simple bootstrap is at least as good and often better. For now researchers would be best advised to use a range of estimators and compare estimates for robustness

Pockets of Privilege: A Historical, Spatial, and Political Economy Analysis of Industrial Zones in Palestine

This article argues that industrial zones in Palestine do not effectively promote Palestinian economic development. The article rests on a historical, spatial, and economic analysis of the political economy of industrial zones in the West Bank and the Gaza Strip. By examining the nature and functionality of these zones through different methodological lenses, it is clear that the industrial zones in Palestine fail on two levels. Firstly, as successful export-processing zones and employment generating programs, the zones are unable to deliver their intended results. On the other hand, even when they do succeed, their performance is limited and does not contribute to a holistic, democratic, and egalitarian notion of economic development. In fact, the benefits accrued are often channeled to Palestinian elites and foreign capital, at the expense of popular Palestinian economic needs such as viable employment, healthcare, housing, food security, and domestic investment. Moreover, the zones work well within the confines of the Israeli Occupation and seem to entrench aspects of its overarching architecture. Lastly, this article argues that industrial zones in Palestine are elements in a wider political and economic project that is being increasingly defined by political, economic, and spatial fragmentation. The emerging social topography is in fact a spatial effect produced by the convergence of Palestinian capitalist class power, international financial institutions (IFIs), the Israeli Occupation, and the expansion of foreign capital. The effect is a future Palestinian state that is highly undemocratic, corrupt, and rife with inequality.

TARGETED LOCALIZATION OF MICROTUBULE-SEVERING ENZYMES TO CREATE NEW LOCAL TOOLS TO STUDY CELL DIVISION

Microtubules are polymeric protein filaments made of the monomeric alpha-beta tubulin heterodimer. They are important for physical attributes of the cell such as shape and structure, and drive essential processes such as cell division, cell migration, and active transport of metabolites. This occurs through the control of microtubules in space and over time through the lifetime of the cell. The shape and interior rearrangements are created by a diverse group of microtubule-associated proteins. When this regulation goes awry, microtubules location, stiffness, and structure are compromised, which is what is seen in diseases such as Alzheimer’s. Multiple microtubule networks can exist within a single cell under distinct spatiotemporal regulators. These networks remain poorly studied because current methods to disrupt the microtubule cytoskeleton do not easily provide rapid, local control with standard cell manipulation reagents. Here, we develop a new microtubule-disruption tool based on katanin p60 severing activity and demonstrate proof-of-principle by targeting it to kinetochores in DrosophilamelanogasterS2 cells. Specifically, we show that human katanin p60 can remove microtubule polymer mass in S2 cells and an increase in misaligned chromosomes when globally overexpressed. When targeted to the kinetochores via Mis12, we were able to recapitulate the misalignment only when using a phosphorylation-resistant mutant. Our results demonstrate that targeting an active version of katanin p60 to the kinetochore can reduce the fidelity of achieving full chromosome alignment in metaphase and could serve as a microtubule disruption tool for the future

The Role of Attachment Style on Preference for Arranged Marriage

This study investigated the role attachment style plays in preference for arranged marriage among single, non-married Indians. It was conducted online using a survey company (Survata) with the requirement that participants be interested in an arranged marriage, be between 18-40 years of age and not be married. The survey was accessed through an online - link which could be located via any internet browser. Respondents included two hundred and seven respondents, who completed three questionnaires concerning their preference for an arranged marriage, attachment style, and acculturation and religious commitment. Data were analyzed using ANOVA and ANCOVA. The results indicate that attachment avoidance, attachment anxiety, religious commitment and acculturation play some role in arranged marriage preference. The Preoccupied attachment (high anxiety and low avoidance) style has the greatest impact on preference for arranged marriage. Acculturation also plays a role in preference for arranged marriage whereas an increase in religious commitment is correlated with a decline in arranged marriage preference. Attachment avoidance and acculturation to the Indian culture seem to play the biggest individual roles. Further analyses showed that the effect of attachment avoidance on preference for arranged marriage is mediated by acculturation but not be religious commitment. The results did not support expectations that attachment anxiety alone or religious commitment alone significantly predict preference for arranged marriage

Distance from a fishing community explains fish abundance in a no-take zone with weak compliance

There are numerous examples of no-take marine reserves effectively conserving fish stocks within their boundaries. However, no-take reserves can be rendered ineffective and turned into ‘paper parks’ through poor compliance and weak enforcement of reserve regulations. Long-term monitoring is thus essential to assess the effectiveness of marine reserves in meeting conservation and management objectives. This study documents the present state of the 15-year old no-take zone (NTZ) of South El Ghargana within the Nabq Managed Resource Protected Area, South Sinai, Egyptian Red Sea. Previous studies credited willing compliance by the local fishing community for the increased abundances of targeted fish within the designated NTZ boundaries compared to adjacent fished or take-zones. We compared benthic habitat and fish abundance within the NTZ and the adjacent take sites open to fishing, but found no significant effect of the reserve. Instead, the strongest evidence was for a simple negative relationship between fishing pressure and distance from the closest fishing village. The abundance of targeted piscivorous fish increased significantly with increasing distance from the village, while herbivorous fish showed the opposite trend. This gradient was supported by a corresponding negative correlation between the amount of discarded fishing gear observed on the reef and increasing distance from the village. Discarded fishing gear within the NTZ suggested decreased compliance with the no-take regulations. Our findings indicate that due to non-compliance the no-take reserve is no longer functioning effectively, despite its apparent initial successes and instead a gradient of fishing pressure exists with distance from the nearest fishing community