Andrew P Goldberg

University of Maryland, Baltimore | UMB · Department of Medicine

Background: The combination of neuromuscular electrical stimulation (NMES) with high protein supplementation (HPRO) to preserve muscle mass and function has not been assessed in ICU patients. We compared the effects of a multimodal intervention combining NMES and HPRO with mobility and strength rehabilitation program (NMES+HPRO+PT) to standardized...

Purpose: The metabolic syndrome (MetS) is a systemic disorder associated with reduced atheroprotective gynoid fat and bone mineral content (BMC). The goal of this pilot study was to assess whether administration of icosapent ethyl (IPE), a purified formulation of eicosapentaenoic acid, would maintain gynoid fat and BMC over a 9-month treatment per...

Background: Atherosclerosis of the carotid bifurcation with plaque formation causes asymptomatic carotid artery stenosis (ACAS), which may also be associated with cerebral hypoperfusion. Cerebral hypoperfusion adversely affects multiple aspects of mobility and cognition. This study tests the hypothesis that community-dwelling older adults with a 5...

Purpose: To compare the effects of adding a progressive multimodal rehabilitation program to usual care (MRP + UC) versus UC alone on 1) functional mobility, strength, endurance and 2) ventilator weaning and discharge status of patients with ICU-acquired weakness (ICUAW) receiving prolonged mechanical ventilation (PMV). Methods: Randomized pilot...

We consider combinatorial algorithms for the minimum-cost flow problem on networks with unit capacities, and special cases of the problem. Historically, researchers have developed special-purpose algorithms that exploit unit capacities. In contrast, for the maximum flow problem, the classical blocking flow and push-relabel algorithms for the genera...

Objective: To determine the 6-month follow-up effects after intentional 6-month weight loss alone (WL) and after weight loss with aerobic exercise (AEX + WL) on body composition, glucose metabolism, and cardiovascular disease risk factors in older postmenopausal women and to identify the mechanisms for weight regain. Methods: Women (n = 65, BMI...

Purpose: The study is to compare the Modified Physical Performance Test (MPPT) and Short Physical Performance Battery (SPPB) as metrics of mobility and function in older men with peripheral arterial disease (PAD). Materials and methods: A total of 51 men (55-87 years) with PAD underwent functional testing including the SPPB, MPPT, Walking Impair...

Objective: Resistance training (RT) reduces fatigue and improves physical function and quality of life (QOL) in breast cancer survivors (BCS). This may be related to reductions in systemic and tissue-specific inflammation. This pilot study examines the hypothesis that RT induces changes in systemic and tissue-specific inflammation that contribute...

Background: Older, critically ill patients receiving mechanical ventilation (MV) are more susceptible to ICU-related sarcopenia due to undernutrition, preexisting comorbidities, and physical deconditioning. We developed an intervention (ExPrES) which incorporates mobility and strengthening exercise (Ex), high-protein supplementation (Pr) and neurom...

Evidence supports resistance training (RT) as a non-pharmacological therapy to improve quality of life (QOL), fatigue, and physical function in breast cancer survivors (BCS). Less is known about the effects of RT on metabolism and systemic and tissue inflammation. The aim of this study was to determine the effects of RT on inflammation and whether...

Background/aims: The purpose was to determine whether lifestyle interventions have different effects on regional fat in women with normal glucose tolerance vs. impaired glucose tolerance (NGT vs. IGT). Methods: Changes in glucose metabolism (2-h oral glucose-tolerance tests), android to gynoid fat mass ratio (dual energy X-ray absorptiometry [DX...

Computing driving directions has motivated many shortest path algorithms based on preprocessing. Given a graph, the preprocessing stage computes a modest amount of auxiliary data, which is then used to speed up online queries. In practice, the best algorithms have storage overhead comparable to the graph size and answer queries very fast, while exa...

We consider the hub label optimization problem, which arises in designing fast preprocessing-based shortest-path algorithms. We give O(log n)-approximation algorithms for the objectives of minimizing the maximum label size (ℓ∞-norm) and simultaneously minimizing a constant number of ℓp-norms. Prior to this, an O(log n)-approximation algorithm was k...

Objectives: This study examines the hypothesis that lower adipose tissue lipoprotein lipase (LPL) activity and a limited capacity for subcutaneous adipocyte expansion will be associated with metabolic syndrome (MSyn) in postmenopausal women who are overweight and obese. Methods: Women (N = 150; age 60 ± 1 year; BMI: 31.5 ± 0.3 kg m(-2); mean ± s...

Objective Breast cancer survivors (BCS) are at high risk for the development of obesity, type 2 diabetes mellitus, and metabolic syndrome. There is increasing interest in the association between depression and metabolic dysfunction, which is relevant in this population as depression is often present in the chronic phase of cancer recovery. Thus, th...

Background: The metabolic syndrome (MetS) is highly prevalent and associated with an increased risk for type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). Lifestyle recommendations to treat MetS often include the replacement of saturated fats (SFAs) and monosaccharides with unsaturated fat. However, it is unclear whether metabolic p...

Background: Skeletal muscle capillary rarefaction limits the transcapillary transport of nutrients and oxygen to muscle and may contribute to sarcopenia and functional impairment in older adults. We tested the hypothesis that skeletal muscle capillarization and exercise capacity (VO2max) are lower in sarcopenic than in nonsarcopenic older adults a...

All current navigation systems return efficient source-to-destination routes assuming a "one-size-fits-all" set of objectives, without addressing most personal preferences. Although they allow some customization (like "avoid highways" or "avoid tolls"), the choices are very limited and require some sophistication on the part of the user. In this pa...

Intramuscular signaling and glucose transport mechanisms contribute to improvements in insulin sensitivity after aerobic exercise training. This study tested the hypothesis that increases in skeletal muscle capillary density (CD) also contribute to exercise-induced improvements in whole-body insulin sensitivity (M/I) independent of other mechanisms...

We propose the first routing engine for computing driving directions in large-scale road networks that satisfies all requirements of a real-world production system. It supports arbitrary metrics (cost functions) and turn costs, enables real-time queries, and can incorporate a new metric in less than a second, which is fast enough to support real-ti...

In this study, we examined the association between 25-hydroxyvitamin D (25(OH)D) concentration and successful weaning from mechanical ventilation in a cohort of ICU survivors requiring prolonged mechanical ventilation. This was a retrospective cohort study of ICU survivors admitted to a long-term acute care hospital. Demographic data were extracted...

Objective To determine whether higher subcutaneous adipose tissue lipoprotein lipase activity (AT-LPLA) is associated with greater triglyceride (TG) storage in subcutaneous adipose tissue (SAT), thereby reducing visceral adipose tissue (VAT) accumulation and metabolic dysfunction.Methods Obese postmenopausal women (60 ± 1 years, mean ± SEM; N = 101...

Hub Labeling (HL) is a data structure for distance oracles. Hierarchical HL (HHL) is a special type of HL, that received a lot of attention from a practical point of view. However, theoretical questions such as NP-hardness and approximation guarantee for HHL algorithms have been left aside. In this paper we study HL and HHL from the complexity theo...

Aging is associated with a decline in maximal aerobic capacity (VO2max) that may be attenuated by chronic endurance exercise. This case study chronicles the changes in marathon times in a 91 year old man who completed 627 marathons and 117 ultramarathons over 42 years. He began running marathons at age 48. His yearly best times remained fairly cons...

We introduce the Excesses Incremental Breadth-First Search (Excesses IBFS) algorithm for maximum flow problems. We show that Excesses IBFS has the best overall practical performance on real-world instances, while maintaining the same polynomial running time guarantee of O(mn 2) as IBFS, which it generalizes. Some applications, such as video object...

Background Recovering useful hand function after stroke is a major scientific challenge for patients with limited motor recovery. We hypothesized that sequential training beginning with proximal bilateral followed by unilateral task oriented training is superior to time-matched unilateral training alone. Proximal bilateral training could optimally...

Techniques are described for graph partitioning, and in particular, graph bisection. A lower bound is provided that is computed in near-linear time. These bounds may be used to determine optimum solutions to real-world graphs with many vertices (e.g., more than a million for road networks, or tens of thousands for VLSI and mesh instances). A packin...

We present a versatile and scalable algorithm for computing exact distances on real-world networks with tens of millions of arcs in real time. Unlike existing approaches, preprocessing and queries are practical on a wide variety of inputs, such as social, communication, sensor, and road networks. We achieve this by providing a unified approach base...

The prevalence of diabetes increases with age, driven in part by an absolute increase in incidence among adults aged 65 years and older. Individuals with diabetes are at higher risk for cardiovascular disease, and age strongly predicts cardiovascular complications. Inflammation and oxidative stress appear to play some role in the mechanisms underly...

Some of the basic techniques behind efficient maximum flow algorithms are studied. A 2013 algorithm of Orlin achieves a strongly polynomial bound for the maximum flow problem, as well as an O(n2/log n)bound for m = O(n). This result is quite sophisticated and uses a combination of ideas from maximum flow, minimum cost flow, and dynamic connectivity...

The Hub Labeling algorithm (HL) is an exact shortest path algorithm with excellent query performance on some classes of problems. It precomputes some auxiliary information (stored as a label) for each vertex, and its query performance depends only on the label size. While there are polynomial-time approximation algorithms to find labels of approxim...

Graph partitioning techniques are based on the notion of natural cuts. A filtering phase performs a series of minimum cut computations to identify and contract dense regions of the graph. This reduces the graph size significantly, but preserves its general structure. An assembly phase uses a combination of greedy and local search heuristics to asse...

We identified normal vs. abnormal 25-hydroxyvitamin D [25(OH)D] concentrations by examining the relation of 25(OH)D to non-bone-related measures (plasma glucose, insulin resistance, lipids, blood pressure, fitness, obesity, and regional adiposity) and asking whether there is a 25(OH)D concentration above and below which the relation between 25(OH)D...

The study goal was to determine the effect of weight loss (WL) alone and with aerobic exercise (WL + AEX) on serum amyloid A (SAA) levels and adipose SAA secretion from gluteal and abdominal depots. Ninety-six overweight or obese postmenopausal women undertook a 6-month WL alone (n = 47) or with AEX training (n = 49) (6 months WL and WL + AEX are c...

OBJECTIVE Transcapillary transport of insulin is one determinant of glucose uptake by skeletal muscle; thus, a reduction in capillary density (CD) may worsen insulin sensitivity. Skeletal muscle CD is lower in older adults with impaired glucose tolerance (IGT) compared with those with normal glucose tolerance and may be modifiable through aerobic e...

Objectives To examine the relationships between plasma and tissue markers of systemic and vascular inflammation and obesity and insulin resistance and determine the effects of aerobic exercise training plus weight loss (AEX+WL) and weight loss (WL) alone on these biomarkers.DesignProspective controlled study.SettingVeterans Affairs Medical Center a...

Objective People with type 2 diabetes have reduced cardiorespiratory fitness and metabolic impairments that are linked to obesity and often occur prior to the development of type 2 diabetes. We hypothesized that obese, older adults with impaired glucose tolerance (IGT) have lower ability to shift from fat to carbohydrate oxidation when transitionin...

We present a novel exact algorithm for the minimum graph bisection problem, whose goal is to partition a graph into two equally-sized cells while minimizing the number of edges between them. Our algorithm is based on the branch-and-bound framework and, unlike most previous approaches, it is fully combinatorial. We introduce novel lower bounds based...

The purpose of this study was to determine the effects of 6-month aerobic exercise training + weight loss (AEX + WL) on basal and insulin activation of glycogen synthase, basal citrate synthase activity, and Akt and AS160 phosphorylation in older, overweight/obese insulin-resistant men (n = 14; 63 ± 2 years; body mass index, 32 ± kg/m2). Muscle sam...

Alternative routes to an optimal route may be determined and presented to a user via a computing device. Alternative routes are selected from candidate routes that meet admissibility criteria. In an implementation, admissibility of a candidate route (in order for it to be considered an alternative route) may be determined based on three criteria: “...

Similarity estimation between nodes based on structural properties of graphs is a basic building block used in the analysis of massive networks for diverse purposes such as link prediction, product recommendations, advertisement, collaborative filtering, and community discovery. While local similarity measures, based on properties of immediate neig...

Optimum journeys in public transportation networks are determined. The determination of Pareto optimal journeys from one stop to another stop in a public transportation network uses the criteria travel time and minimum transfers. A technique for bi-criteria journey planning using the aforementioned criteria in public transportation networks operate...

We consider the problem of approximating optimal hub labelings in the context of labeling algorithms for the shortest path problem. A previous result was a O(logn) approximating for minimizing the total label size. We give an O(logn)-approximation algorithm for the maximum label size. We also give O(logn)-approximation algorithms for natural genera...

Given a weighted graph, a distance oracle takes as an input a pair of vertices and returns the distance between them. The labeling approach to distance oracle design is to precompute a label for every vertex so that the distances can be computed from the corresponding labels, without looking at the graph. In the hub labeling algorithm (HL), a verte...

The hub labels (HL) algorithm is the fastest known technique for computing driving times on road networks, but its practical applicability can be limited by high space requirements relative to the best competing methods. We develop compression techniques that substantially reduce HL space requirements with a small performance penalty.

In the context of distance oracles, a labeling algorithm computes vertex labels during preprocessing. An $s,t$ query computes the corresponding distance from the labels of $s$ and $t$ only, without looking at the input graph. Hub labels is a class of labels that has been extensively studied. Performance of the hub label query depends on the label s...

Objective Sequential compression devices or ambulation prevent deep venous thrombosis (DVT) by enhancing venous blood flow in the lower extremity. However, compression therapy or ambulation may not be possible in patients with lower extremity surgery or trauma. We therefore determined whether upper body exercise increases venous blood flow in the l...

The non-negative single-source shortest path (NSSP) problem is solved on a graph by using a preprocessing phase and then, in a query phase, computing the distances from a given source in the graph with a linear sweep over all the vertices. Contraction hierarchies may be used in the preprocessing phase and in the query phase. Optimizations may inclu...

This paper introduces HLDB, the first practical system that can answer exact spatial queries on continental road networks entirely within a database. HLDB is based on hub labels (HL), the fastest point-to-point algorithm for road networks, and its queries are implemented (quite naturally) in standard SQL. Within the database, HLDB answers exact dis...

Background: Androgen deprivation therapy (ADT) for prostate cancer (PCa) is associated with weakness, fatigue, sarcopenia, and reduced quality of life (QoL). Black men have a higher incidence and mortality from PCa than Caucasians. We hypothesized that despite ADT, strength training (ST) would increase muscle power and size, thereby improving body...

We study hierarchical hub labelings for computing shortest paths. Our new theoretical insights on the structure of hierarchical labels lead to faster preprocessing algorithms, making the labeling approach practical for a wider class of graphs and enabling real-time traffic updates on road networks. We also find smaller labels, improving the query s...

Department of Veterans Affairs (VA) Geriatric Research, Education and Clinical Centers (GRECCs) originated in 1975 in response to the rapidly aging veteran population. Since its inception, the GRECC program has made major contributions to the advancement of aging research, geriatric training, and clinical care within and outside the VA. GRECCs were...

We present a novel exact algorithm for the minimum graph bisection problem, whose goal is to partition a graph into two equally-sized cells while minimizing the number of edges between them. Our algorithm is based on the branch-and-bound framework and, unlike most previous approaches, it is fully combinatorial. We present stronger lower bounds, imp...

We illustrate the use of the scientific method in algorithmics by surveying recent developments in route planning on road networks. Several speed-up techniques proposed in the past decade are intuitive, elegant, and very efficient in practice, but lacked a theoretical explanation of their observed performance. By introducing a formal definition of...

Our objective was to test the hypothesis that a common polymorphism in the hepatic lipase (HL) gene (LIPC -514C>T, rs1800588) influences aerobic exercise training-induced changes in TG, very-low-density lipoprotein (VLDL), and high-density lipoprotein (HDL) through genotype-specific increases in lipoprotein lipase (LPL) activity and that sex may af...

Maximum flow and minimum s-t cut algorithms are used to solve several fundamental problems in computer vision. These problems have special structure, and standard techniques perform worse than the special-purpose Boykov-Kolmogorov (BK) algorithm. We introduce the incremental breadth-first search (IBFS) method, which uses ideas from BK but augments...

We present a novel algorithm to solve the nonnegative single-source shortest path problem on road networks and other graphs with low highway dimension. After a quick preprocessing phase, we can compute all distances from a given source in the graph with essentially a linear sweep over all vertices. Because this sweep is independent of the source, w...

The prevalence of the metabolic syndrome (MetSyn) approaches 50% in postmenopausal women. This study examines the efficacy of lifestyle modification for the treatment of MetSyn and its associated risk for cardiovascular disease and diabetes in this population. This prospective controlled study examines the effects of a 6-month weight loss and low-i...

We present an algorithm to compute shortest paths on continental road networks with arbitrary metrics (cost functions). The approach supports turn costs, enables real-time queries, and can incorporate a new metric in a few seconds—fast enough to support real-time traffic updates and personalized optimization functions. The amount of metric-specific...

We present a novel approach to graph partitioning based on the notion of cuts. Our algorithm, called PUNCH, has two phases. The first phase performs a series of minimum-cut computations to identify and contract dense regions of the graph. This reduces the graph size, but preserves its general structure. The second phase uses a combination of greedy...

The β(2)-adrenergic receptor (ADRB2) mediates obesity, cardiorespiratory fitness, and insulin resistance. We examined the hypothesis that ADRB2 Arg16Gly-Gln27Glu haplotype is associated with body composition, glucose tolerance, and insulin sensitivity in obese, postmenopausal women. Obese (>35% body fat), postmenopausal (age 45-75 years) women (n =...

We study the problem of computing batched shortest paths in road networks efficiently. Our focus is on computing paths from a single source to multiple targets (one-to-many queries). We perform a comprehensive experimental comparison of several approaches, including new ones. We conclude that a new extension of PHAST (a recent one-to-all algorithm)...

Abraham et al. [SODA 2010] have recently presented a theoretical analysis of several practical point-to-point shortest path algorithms based on modeling road networks as graphs with low highway dimension. Among the methods they analyzed, the one with the best time bounds is the labeling algorithm. Their results suggest that the algorithm is interes...

This randomized controlled trial tests the efficacy of bilateral arm training with rhythmic auditory cueing (BATRAC) versus dose-matched therapeutic exercises (DMTEs) on upper-extremity (UE) function in stroke survivors and uses functional magnetic resonance imaging (fMRI) to examine effects on cortical reorganization. A total of 111 adults with ch...

We study the problem of finding good alternative routes in road networks. We look for routes that are substantially different from the shortest path, have small stretch, and are locally optimal. We formally define the problem of finding alternative routes with a single via vertex, develop efficient algorithms for it, and evaluate them experimentall...