bluuebunny/crossref_metadata_2025 huggingface dataset:
Familial Hypocalciuric Hypercalcemia in a Woman with Metastatic Breast Cancer: A Case Report of Mistaken Identity
Authors: Marcocci Claudio , Borsari Simona , Pardi Elena , Dipollina Giada , Giacomelli Tamara , Pinchera Aldo , Cetani Filomena
Published: November 2003

We describe a 45-yr-old woman with metastatic breast cancer and hypercalcemia previously diagnosed as hypercalcemia of malignancy and treated with bisphosphonates without changes of serum calcium (s-Ca). At the time of our evaluation, biochemical data [s-Ca, 10.8 mg/dl (2.70 mmol/liter); PTH, 24.4 pg/ml (2.6 pmol/liter); 24-h urinary calcium, 160 mg (4.0 mmol); calcium/creatinine clearance, 0.007] suggested the diagnosis of familial hypocalciuric hypercalcemia. Three of five relatives had mild hypercalcemia [s-Ca, 10.7–11.2 mg/dl (2.67–2.80 mmol/liter)] and detectable serum PTH [24.5–29.0 pg/ml (2.6–3.1 pmol/liter)]. A novel heterozygous I212T missense mutation in exon 4 of the calcium-sensing receptor (CaR) gene was found in the proband and affected relatives but not in unaffected relatives. Expression of the mutant I212T CaR in COS-7 cells resulted in no response of inositol phosphates to any calcium concentration. The calcium dose-response curve of the coexpressed receptors [wild-type/I212T] suggested that the mutant receptor interferes with the function of the wild-type receptor. In conclusion, we describe a case of familial hypocalciuric hypercalcemia due to a novel CaR mutation, in a woman with breast cancer in whom hypercalcemia was initially attributed to hypercalcemia of malignancy.
Efficacy and Safety of Human Parathyroid Hormone-(1–84) in Increasing Bone Mineral Density in Postmenopausal Osteoporosis
Authors: Hodsman Anthony B. , Hanley David A. , Ettinger Mark P. , Bolognese Michael A. , Fox John , Metcalfe Anna J. , Lindsay Robert
Published: November 2003

Daily sc injections of N-terminal analogs of PTH increase bone mass and decrease fractures in osteoporotic women. We investigated the efficacy and safety of human PTH-(1–84) (full-length PTH) in the treatment of postmenopausal osteoporosis in a double-blind, placebo-controlled study. The women (n = 50–53/group) self-administered PTH (50, 75, or 100 μg) or placebo by daily sc injection for 12 months. PTH treatment induced time- and dose-related increases in lumbar spine bone mineral density (BMD). The 100-μg dose increased BMD significantly at 3 months (+2.0%) and 12 months (+7.8%). BMD underestimated the anabolic effect of PTH in lumbar spine (bone mineral content, +10.0%) because bone area increased significantly (+2.0%). A nonsignificant decrease (−0.9%) in total hip BMD occurred during the first 6 months with the 100-μg dose, but this trend reversed (+1.6%) during the second 6 months. Bone turnover markers increased during the first half of the study and were maintained at elevated levels during the second 6 months. Protocol compliance was excellent (95–98%), and treatment was generally safe and well tolerated. Dose-related incidences of transient hypercalcemia occurred, but only one patient (100-μg group) was withdrawn because of repeated hypercalcemia. Thus, full-length PTH was efficacious and safe over 12 months.
Characterization of Endozepines in the Human Testicular Tissue: Effect of Triakontatetraneuropeptide on Testosterone Secretion
Authors: Duparc Celine , Lefebvre Herve , Tonon Marie-Christine , Vaudry Hubert , Kuhn Jean-Marc
Published: November 2003

Previous studies have shown that endozepines, i.e. endogenous ligands of benzodiazepine (BZD) receptors, stimulate steroidogenesis in adrenocortical and Leydig cells. In the present report, we have investigated the presence and action of endozepines in the human testis. Immunohistochemical labeling revealed the occurrence of endozepine-like immunoreactivity in Leydig, Sertoli, and germ cells. HPLC analysis combined with a specific RIA resolved two immunoreactive peaks that coeluted with synthetic octadecaneuropeptide (ODN) and triakontatetraneuropeptide (TTN). RT-PCR amplification showed that the mRNA encoding the endozepine precursor diazepam-binding inhibitor is expressed in the human testis. The action of endozepines on testosterone production was studied in vitro using perifused human testicular fragments. Administration of TTN provoked a dose-dependent increase in testosterone secretion, whereas ODN had no effect. The stimulatory action of TTN on testosterone production was totally blocked by flunitrazepam, a peripheral-type BZD receptor antagonist/central-type BZD receptor (CBR) agonist. Conversely, the CBR agonist clonazepam and the CBR antagonist flumazenil did not affect testosterone secretion. Collectively, these results suggest that, in the human testicular tissue, TTN may exert an intracrine and/or paracrine control of steroidogenesis through activation of a peripheral-type BZD receptor.
Differential Responses of Circulating Ghrelin to High-Fat or High-Carbohydrate Meal in Healthy Women
Authors: Monteleone Palmiero , Bencivenga Rachele , Longobardi Nicola , Serritella Cristina , Maj Mario
Published: November 2003

The effects of specific nutritional factors on ghrelin secretion have not been investigated in humans. Therefore, we assessed ghrelin responses to a high-carbohydrate meal (1217 kcal with 77% carbohydrates, 10% protein, and 13% lipids) and to an isocaloric high-fat meal (15% carbohydrates, 10% proteins, and 75% lipids) in 14 nonobese healthy women. Eleven subjects also rated their hunger feelings on visual analog scales. Circulating ghrelin abruptly fell after both meals, but, after the carbohydrate meal, its maximum percent decrease was significantly greater than after the fat meal (P = 0.02). Plasma insulin and glucose levels rose after the meals, but their increases were significantly higher after the carbohydrate meal than after the fat meal. No significant change was observed in circulating leptin after both meals. Moreover, compared with the fat meal, the carbohydrate meal had a significantly greater suppressant effect on hunger feelings. Plasma ghrelin changes were significantly associated with hunger changes (P < 0.007). These findings show that circulating ghrelin is differently suppressed by diet manipulations. The mechanisms responsible for such a phenomenon and its possible implication in the physiology of human satiety remain to be elucidated.
Increased Luteinizing Hormone Secretion in Women with Polycystic Ovary Syndrome Is Unaltered by Prolonged Insulin Infusion
Authors: Patel Ketan , Coffler Mickey S. , Dahan Michael H. , Yoo Richard Y. , Lawson Mark A. , Malcom Pamela J. , Chang R. Jeffrey
Published: November 2003

In PCOS women with insulin resistance, hyperinsulinemia may contribute to inappropriate gonadotropin secretion. To determine whether insulin influences gonadotropin release in PCOS, pulsatile LH secretion and gonadotropin responses to GnRH were evaluated before (phase 1) and during (phase 2) insulin infusion. In phase 1, 11 PCOS and 9 normal women on separate days underwent 1) frequent blood sampling (q 10 min) for 12 h and 2) gonadotropin stimulation by successive doses of GnRH, 2 μg, 10 μg, and 20 μg, administered iv at 4 h intervals over a continuous 12 h. In phase 2, studies were repeated 2 h after initiation of a 12-h hyperinsulinemic-euglycemic clamp (80 mU/m2·min). Administration of insulin to both groups failed to alter mean serum gonadotropin concentrations, LH pulse frequency, or LH pulse amplitude. Moreover, gonadotropin responses to GnRH were unchanged by insulin infusion. In PCOS and normal women, a significant reduction of serum androstenedione was associated with insulin administration, whereas no differences were noted for the remaining androgens and estrogens measured.

These findings demonstrated that in PCOS women, LH secretion and gonadotropin responses to GnRH were not influenced by insulin administration. Insulin infusion had little effect on steroid hormone production with the possible exception of androstenedione. These results suggest that inappropriate LH secretion in PCOS is not a direct consequence of insulin resistance and compensatory hyperinsulinemia.
Phenotypic Heterogeneity in Body Fat Distribution in Patients with Congenital Generalized Lipodystrophy Caused by Mutations in the AGPAT2 or Seipin Genes
Authors: Simha Vinaya , Garg Abhimanyu
Published: November 2003

Congenital generalized lipodystrophy (CGL) is a rare autosomal recessive syndrome characterized by extreme paucity of adipose tissue since birth, acanthosis nigricans, severe insulin resistance, marked hypertriglyceridemia, and early-onset diabetes mellitus. Recently, we reported mutations in the 1-acylglycerol-3-phosphate O-acyltransferase 2 (AGPAT2) gene in CGL pedigrees linked to chromosome 9q34 (CGL1 subtype), and mutations in the Seipin gene were reported in pedigrees linked to chromosome 11q13 (CGL2 subtype). Whether the two subtypes have differences in body fat distribution has not been investigated. We, therefore, compared whole-body adipose tissue distribution by magnetic resonance imaging in 10 CGL patients, of whom seven (six females, one male) had CGL1 and three (two males, one female) had CGL2. Both subtypes had marked lack of metabolically active adipose tissue located at most sc, intermuscular, bone marrow, intraabdominal, and intrathoracic regions. Paucity of mechanical adipose tissue in the palms, soles, orbits, scalp, and periarticular regions was noted in CGL2, whereas it was well preserved in CGL1 patients. We conclude that CGL patients with Seipin mutations have a more severe lack of body fat, which affects both metabolically active and mechanical adipose tissue, compared with patients with mutations in the AGPAT2 gene.
Functional, Structural, and Distribution Analysis of the Chorionic Gonadotropin Receptor Using Murine Monoclonal Antibodies
Authors: Funaro Ada , Sapino Anna , Ferranti Bruna , Horenstein Alberto L. , Castellano Isabella , Bagni Bruno , Garotta Gianni , Malavasi Fabio
Published: November 2003

LH and human chorionic gonadotropin (hCG) control steroid production and gametogenesis. They also function as growth factors through interaction with a specific receptor that is a member of the seven-transmembrane receptor family coupled via G proteins to signal pathways involving cAMP and phospholipase C/inositol 3 phosphate.

For this study, monoclonal antibodies (mAbs) were raised against the human LH receptor (LHR)/hCG receptor (hCGR), using Chinese hamster ovary LHR-transfected cells as the immunogen. Two reagents were then selected on the basis of their ability to recognize the full-length transmembrane re-ceptor expressed both by Chinese hamster ovary LHR-transfected cells and by a limited number of tumor cell lines.

One of these mAbs reacts with the LHR/hCGR in tissue sections of both frozen and paraffin-embedded specimens. This unique feature allowed us to map the cytological distribution of LHR/hCGR in human breast tissues at different stages of development in physiological and benign pathological conditions. The same mAb proved to be agonistic: receptor ligation elicits signals that modulate the growth of selected breast tumor cell lines. This observation suggests that the mAb recognizes an epitope that is included in the domain of the receptor involved in the interaction with the natural ligand.
Cross-Unit Competition for a Market Charter: The Enduring Influence of Structure
Authors: Houston Mark B. , Walker Beth A. , Hutt Michael D. , Reingen Peter H.
Published: November 2003

Marketing strategists who operate in turbulent markets face a competitive landscape marked by volatility and evolving market structures. As customer requirements change, an organization that stays in alignment with its markets will form new business units or alter the market charters of existing business units. In a longitudinal study, the authors traced the structural realignments that accompanied a Fortune-500 firm's entry into the Internet market. As the charter moved from a freshly created unit to an established business unit, the authors found support for the prediction that the former organizational structure will continue to shape the identity, beliefs, and social ties of managers. The study highlights the structural, social, and cognitive factors that must be managed as corporate decision makers search for the best strategy–structure fit for an emerging market opportunity.
Marketing Literature Review
Authors: Leonard Myron
Published: November 2003

This section is based on a selection of article abstracts from a comprehensive business literature database. Marketing-related abstracts from more than 125 journals (both academic and trade) are reviewed by JM staff. Descriptors for each entry are assigned by JM staff. Each issue of this section represents three months of entries into the database.

Each entry has an identifying number. Cross-references appear immediately under each subject heading.

The following article abstracts are available online from the ABI/INFORM database, which is published and copyrighted by Bell & Howell Information and Learning. For additional information about access to the database or about obtaining photocopies of the articles abstracted here, please call (800) 521-0600 or write to B&H, 300 N. Zeeb Rd., Ann Arbor, MI 48106.
Customer Profitability in a Supply Chain
Authors: Niraj Rakesh , Gupta Mahendra , Narasimhan Chakravarthi
Published: November 2003

Estimating current profitability at the individual customer level is important to distinguish the more profitable customers from the less profitable ones. This is also a first step in developing estimates of customers' lifetime values. This exercise, however, takes on additional complexities when applied to an intermediary in a supply chain, such as a distributor, because the costs of servicing a retail customer include not only those incurred directly in servicing this customer but also those incurred by the distributor in dealing with its own vendors for goods supplied to this customer. The authors develop a general model and measurement methodology to relate customer profitability to customer characteristics in a supply chain. The authors show how heterogeneity in customer purchasing characteristics leads to important profit implications and illustrate the implementation of the methodology using data from a large distributor that supplies to grocery and other retail businesses.
The Impact of Category Management on Retailer Prices and Performance: Theory and Evidence
Authors: Basuroy Suman , Mantrala Murali K. , Walters Rockney G.
Published: November 2003

Category management (CM) is a recent retail management initiative that aims at improving a retailer's overall performance in a product category through more coordinated buying, merchandising, and pricing of the brands in the category than in the past. Despite tremendous retailer and manufacturer interest in the process of CM and its rapid adoption in the industry, much uncertainty exists about the consequences of CM for channel members. The present study focuses on how a shift to CM by a retailer affects its equilibrium prices, sales, and profitability in a competitive retail setting. On the basis of an analysis of a model of two competing national brand manufacturers that supply two competing common retailers, the authors find that one retailer's adoption of CM increases its average unit price of the category and reduces its sales volume and revenues. However, this retailer can still enjoy an increase in its gross margin profits as competing manufacturers’ wholesale prices fall in the process. Also, the CM adopter's profits are greater than those of a symmetric competing retailer that follows the traditional brand-centered management of a product category when the interbrand competition is high but interstore competition is low. Applying the intervention analysis methodology, the authors empirically test several of these analytical findings, employing a unique data set that contains information about a supermarket chain's weekly average unit prices and sales of the laundry detergent category before and after this product category was moved to CM by the retailer. The propositions that adoption of CM will lead to higher retail prices and lower sales are upheld in this empirical study. The authors discuss the implications of these findings for practitioners and researchers, the limitations of the study, and directions for further research.
Investments in Consumer Relationships: A Cross-Country and Cross-Industry Exploration
Authors: De Wulf Kristof , Odekerken-Schröder Gaby , Iacobucci Dawn
Published: November 2003

This research, investigating retailer–consumer relationships, has three distinct intended contributions: (1) It shows that different relationship marketing tactics have a differential impact on consumer perceptions of a retailer's relationship investment; (2) it demonstrates that perceived relationship investment affects relationship quality, ultimately leading to behavioral loyalty; and (3) it reveals that the effect of perceived relationship investment on relationship quality is contingent on a consumer's product category involvement and proneness to engage in retail relationships. The authors empirically cross-validate the underlying conceptual model by studying six consumer samples in a three-country, transatlantic, comparative survey that investigates two industries.
Dynamic Customer Relationship Management: Incorporating Future Considerations into the Service Retention Decision
Authors: Lemon Katherine N. , White Tiffany Barnett , Winer Russell S.
Published: November 2003

The authors examine the influence of customer future-focused considerations, over and above the effects of satisfaction, on the customer's decision to discontinue a service relationship. The authors find that expected future use and anticipated regret influence this decision. Understanding and managing these future-focused considerations is critical to successful dynamic customer relationship management.
Building Brand Community
Authors: McAlexander James H. , Schouten John W. , Koenig Harold F.
Published: November 2003

A brand community from a customer-experiential perspective is a fabric of relationships in which the customer is situated. Crucial relationships include those between the customer and the brand, between the customer and the firm, between the customer and the product in use, and among fellow customers. The authors delve ethnographically into a brand community and test key findings through quantitative methods. Conceptually, the study reveals insights that differ from prior research in four important ways: First, it expands the definition of a brand community to entities and relationships neglected by previous research. Second, it treats vital characteristics of brand communities, such as geotemporal concentrations and the richness of social context, as dynamic rather than static phenomena. Third, it demonstrates that marketers can strengthen brand communities by facilitating shared customer experiences in ways that alter those dynamic characteristics. Fourth, it yields a new and richer conceptualization of customer loyalty as integration in a brand community.
Strategic Bundling of Products and Prices: A New Synthesis for Marketing
Authors: Stremersch Stefan , Tellis Gerard J.
Published: November 2003

Bundling is pervasive in today's markets. However, the bundling literature contains inconsistencies in the use of terms and ambiguity about basic principles underlying the phenomenon. The literature also lacks an encompassing classification of the various strategies, clear rules to evaluate the legality of each strategy, and a unifying framework to indicate when each is optimal. Based on a review of the marketing, economics, and law literature, this article develops a new synthesis of the field of bundling, which provides three important benefits. First, the article clearly and consistently defines bundling terms and identifies two key dimensions that enable a comprehensive classification of bundling strategies. Second, it formulates clear rules for evaluating the legality of each of these strategies. Third, it proposes a framework of 12 propositions that suggest which bundling strategy is optimal in various contexts. The synthesis provides managers with a framework with which to understand and choose bundling strategies. It also provides researchers with promising avenues for further research.
The Effects of Ingredient Branding Strategies on Host Brand Extendibility
Authors: Desai Kalpesh Kaushik , Keller Kevin Lane
Published: November 2003

A decision of increasing importance is how ingredient attributes that make up a product should be labeled or branded, if at all. The authors conduct a laboratory experiment to consider how ingredient branding affects consumer acceptance of a novel line extension (or one that has not been introduced before) as well as the ability of the brand to leverage that ingredient to introduce future category extensions. The authors study two particular types of novel line extensions or brand expansions: (1) slot-filler expansions, in which the level of one existing product attribute changes (e.g., a scent in Tide detergent that is new to the laundry detergent category) and (2) new attribute expansions, in which an entirely new attribute or characteristic is added to the product (e.g., cough relief liquid added to Life Savers candy). The authors examine two types of ingredient branding strategies by branding the target attribute ingredient for the brand expansion with either a new name as a self-branded ingredient (e.g., Tide with its own EverFresh scented bath soap) or an established, well-respected name as a cobranded ingredient (e.g., Tide with Irish Spring scented bath soap). The results indicate that with slot-filler expansions, a cobranded ingredient facilitates initial expansion acceptance, but a self-branded ingredient leads to more favorable subsequent category extension evaluations. With more dissimilar new attribute expansions, however, a cobranded ingredient leads to more favorable evaluations of both the initial expansion and the subsequent category extension. The authors offer interpretation, implications, and limitations of the findings, as well as directions for further research.
Riding the Saddle: How Cross-Market Communications Can Create a Major Slump in Sales
Authors: Goldenberg Jacob , Libai Barak , Muller Eitan
Published: November 2003

Using data on a large number of innovative products in the consumer electronics industry, the authors find that between one-third and one-half of the sales cases involved the following pattern: an initial peak, then a trough of sufficient depth and duration to exclude random fluctuations, and eventually sales levels that exceeded the initial peak. This newly identified pattern, which the authors call a “saddle,” is explained by the dual-market phenomenon that differentiates between early market adopters and main market adopters as two separate markets. If these two segments—the early market and the main market—adopt at different rates, and if this difference is pronounced, then the overall sales to the two markets will exhibit a temporary decline at the intermediate stage. The authors employ both empirical analysis and cellular automata, an individual-level, complex system modeling technique for generating and analyzing data, to investigate the conditions under which a saddle occurs. The model highlights the importance of cross-market communication in determining the existence of a saddle. At low levels of this parameter, more than 50% of the cases of new product growth involved a saddle. This percentage gradually decreased as the parameter increased, and at values close to the within-market parameters, the proportion of saddle occurrences dropped below 5%.
The Influence of Multiple Store Environment Cues on Perceived Merchandise Value and Patronage Intentions
Authors: Baker Julie , Parasuraman A. , Grewal Dhruv , Voss Glenn B.
Published: November 2003

Research on how store environment cues influence consumers' store choice decision criteria, such as perceived merchandise value and shopping experience costs, is sparse. Especially absent is research on the simultaneous impact of multiple store environment cues. The authors propose a comprehensive store choice model that includes (1) three types of store environment cues (social, design, and ambient) as exogenous constructs, (2) various store choice criteria (including shopping experience costs that heretofore have not been included in store choice models) as mediating constructs, and (3) store patronage intentions as the endogenous construct. They then empirically examine the extent to which environmental cues influence consumers' assessments of a store on various store choice criteria and how those assessments, in turn, influence patronage intentions. The results of two different studies provide support for the model. The authors conclude by discussing the results to develop an agenda for additional research and explore managerial implications.
Air and Ship‐Based Space Launch Vehicles
Authors: Fenn Dale
Published: October 2003

In 1957, the Soviet Union placed the first man‐made object in orbit around the earth. Since then, numerous launch vehicles have been developed to improve the performance, reliability, and cost of placing objects in orbit. By one estimate, roughly 75 active space launch vehicles either have established flight records or are planning an inaugural launch within the year. This does not include the numerous launch vehicles from around the world that are no longer operational such as the Jupiter, Redstone, Juno, Saturn, Scout, Thor, Vanguard, and Conestoga family of rockets from the United States or the N‐1 from the former Soviet Union, to name just a few. Despite the many differences among all of these launch vehicles from both past and present, one common element can be found in all but four of them: they are ground‐launched. Of the four exceptions, two are air‐launched (NOTSNIK and Pegasus), one is ship‐launched (Sea Launch), and one is submarine‐launched (Shtil). It is important to keep in mind that numerous air‐launched and ship‐launched suborbital launch systems are in use by militaries, commercial entities, and educational institutions. However, the four mentioned are the only mobile launch systems that can place objects into a sustainable Earth orbit. The launch systems and the advantages and disadvantages of these systems are discussed.
Moon
Authors: Spudis Paul D.
Published: October 2003

The Moon, the natural satellite of Earth, has positively affected our development in many profound ways. Its orbital presence helps stabilize Earth's axial precession and thus, prevents the alternating extremes of climate that some planets, such as Mars, experience. This equitable climate makes Earth a habitable world. The ocean tides induced by the Moon probably permitted vertebrate life to emerge from the sea more than 300 million years ago, leading to the development of land fauna and ultimately, to ourselves. Thus in a very real sense, we are here because the Moon exists.

Now, the Moon is exerting its beneficial influence on us once again by its existence. The Moon is the first milepost in humanity's movement into the solar system. We must pass by the Moon's orbit to go anywhere else in space. Thus, nature has provided us with a natural “way station,” a place to learn how to live and work in space, refuel, and refresh our spacecraft. In addition to these benefits, the Moon also happens to be a rather interesting place. Its surface contains a record of the important events that occurred in the early history of Earth. Moreover, it is an excellent platform to observe the Universe around us. In all of these ways, the Moon is an important part of our movement into space. Basic properties and motions of the moon are given as well as its origin and structure.

Scientific data from the Apollo and post Apollo missions are discussed. Later missions are designed to look for water on the moon water could help support a lunar colony on the moon as an outpost for exploration.
NASA
Mission Operation Control Center at Johnson Space Center
Authors: Lunney Glynn S.
Published: October 2003

As the Space Task Group (STG) began to relocate to Houston, Texas, from Langley Field, Virginia, in 1962, the last of the Mercury flights were still being supported from the Mercury Control Center (MCC) at the Cape Canaveral Air Force Station in Florida. In those early days, dramatic change was underway throughout the manned space program. Galvanized by President Kennedy's Moon challenge in 1961, Gemini and Apollo began to take form in the engineering, design, and manufacturing organizations throughout the country. The learning curves were very steep in all of the disciplines. This was equally true in the control of flight operations, as they were facilitated in the first control center in Florida and at key remote sites around the globe.

The flight operations function (becoming known as flight control) faced new changes for the upcoming programs—missions were much more complex due to rendezvous, extra vehicular activity (EVA), and lunar challenges. Telemetry and command systems were changing from analog to digital, reliable global communications were enabling a more centralized control center with fewer remote sites, and the schedule demanded extensive training with concurrent training for one flight while actively performing another simultaneously. All of these considerations and others led to the conclusion that the new Mission Control Center must be colocated with the flight control team in Houston.

This article details the various missions launched from Houston basic concepts of flight control are discussed. Missions in the Gemini, Apollo, Skylab, Apollo‐Soyuz, Space Shuttle, and Challenger programs are discussed. Space station preparations are considered.
Deep Space Network, Evolution of Technology
Authors: Layland James W. , Rauch Lawrence L. , Mudgway Douglas J. , Lesh James R.
Published: October 2003

The Deep Space Network (DSN), managed by the California Institute of Technology's Jet Propulsion laboratory (JPL), has provided vital communications and navigation services for NASA deep space exploration missions for more than 40 years. The remarkable technical achievements of the planetary exploration program executed by NASA would not have been possible without the extensive and sophisticated communications and data handling systems that comprise the Deep Space Network.

The principal facilities of the DSN are three major ground station complexes, one in the United States (Goldstone, California), one near Madrid, Spain, and one near Canberra, Australia. Each of the complexes has several tracking antennae; the largest has a diameter of 70 meters, and smaller ones have diameters of 11–34 meters. In addition to antennae, the DSN also has a complex of computers and signal processing capabilities that permit very thorough and sophisticated analysis of signals sent back from distant spacecraft.

In addition to receiving data from very distant spacecraft, the facilities of the network are also used to control the spacecraft. The network and the associated spacecraft are designed so that if a failure of a spacecraft should occur, there are often means available to effect a recovery. The continuing improvements in the technology of the network have greatly increased the useful lives and capabilities of the spacecraft that use the network.

No history of the DSN would be complete without full appreciation of the contribution made by advanced technology to the successful development of the Network. The wellspring of new and innovative ideas for increasing the existing capability of the Network, improving reliability, operability, and cost‐effectiveness, and for enabling recovery from potential mission‐threatening situations has resided, from the very beginning of the Network's history, in a strong program of advanced technology, research, and development.
Venus Missions
Authors: Moroz Vasily I. , Bazilevsky Alexander T.
Published: October 2003

Launches of Soviet spacecraft to Venus were started in 1961. A full list of them is presented. The first success in space studies of Venus was achieved by the Soviets in 1967. Venera 4 reached the planet and fulfilled its mission. It was separated from the bus and entered the atmosphere, slowing as it descended. The parachute opened, and measurements of the atmospheric properties were taken down to an altitude 25 km above the surface. The probe was destroyed there due to high density and/or high temperature. Venera 4 was the first successful planetary atmospheric probe. The U.S. flyby probe, Mariner 5, arrived at Venus 1 day after Venera 4 and conducted some remote studies of the atmosphere. Then for about 10 years, NASA did nothing to explore Venus besides the Mariner 10 flyby on its way to Mercury. In contrast, the Soviet Union at that time was sending missions to Venus regularly, in the beginning using each astronomical window (about a 1.5‐year gap) and later each second window (about 3 years).

This article briefly outlines the Soviet scientific output. Results of the studies include the atmosphere and its interaction with the solar wind and details on the surface of Venus. A lot of valuable information about Venus was obtained by the Soviet (and also U.S.) missions to this planet. Most of the data (although still not all) has been carefully analyzed. A set of new goals and new possibilities was identified by this activity. Possibly it is time now for a return to the exploration of Venus on a new level.
Cardiovascular System in Space
Authors: Ramsdell Craig D. , Cohen Richard J.
Published: October 2003

The microgravity environment of space is well tolerated by the cardiovascular system over during periods ranging from weeks to several months. In many ways, the heart, peripheral vasculature, and central cardiovascular control system are exposed to fewer challenges in microgravity than on Earth. Consider the simple act of standing upright in the normal gravity field of Earth. Assumption of an upright posture on Earth causes a redistribution of blood volume to the lower parts of the body, resulting in an increase in blood pressure in dependent blood vessels and a decrease in arterial blood pressure above the level of the heart. The cardiovascular system must quickly compensate for these changes by altering the heart rate, the force of contraction of the heart, and the resistance of the blood vessels to maintain enough blood flow to the brain to prevent loss of consciousness. Under weightless conditions, however, there are no postural changes in blood volume and pressure, which greatly reduces the demands placed on the cardiovascular system to maintain homeostasis. Furthermore, moving about in microgravity requires far less energy than required in gravity, which places less demand on the cardiovascular system.

During the long term, however, many physiological systems become dysfunctional when they are not required to perform at a normal level. For example, the muscles and bones of a leg immobilized in a cast for a month or two become atrophied and weak. Similarly, the relatively unchallenging environment of microgravity ultimately results in dysfunctional changes in the heart, the vasculature, and the central cardiovascular control system that may have harmful consequences during spaceflight and upon reexposure of the human organism to a gravitational field.

For example, many astronauts cannot maintain normal blood pressure and feel dizzy or faint when standing upright immediately following spaceflight, a condition calledorthostatic intolerance. This may impair their ability to get out of a spacecraft quickly should an emergency arise, or to perform meaningful work upon arrival in a gravitational field, for example, after a trip to Mars. There are also reports of rhythmic disturbances of the heart (cardiac arrhythmias) during spaceflight and of loss of muscle mass of the heart (cardiac atrophy). The latter two conditions, though less well documented than orthostatic intolerance, represent potentially life‐threatening alterations in cardiovascular function. Before these problems in are discussed in detail. A brief review of normal cardiovascular physiology is also presented.
Digital Video
Authors: Netravali Arun N.
Published: October 2003

Analog television was developed and standardized in the forties, mainly for over‐the‐air broadcast of entertainment, news, and sports. While a few upward compatible changes have been made in the intervening years, such as color, multi‐channel sound, closed captioning, and ghost cancellation, the underlying analog system has survived a continuous technological evolution that has pervaded all other media. Television has stimulated the development of a global consumer electronics industry that has brought high‐density magnetic recording, high‐resolution displays, and low‐cost imaging technologies from the laboratory into the living room. A vast array of video production processing technologies make high‐quality programming an everyday reality, real‐time on‐site video the norm rather than the exception, and video the historical medium of record throughout the world. Emergence of personal computers and high speed networks has given rise to desktop video to improve productivity for businesses.

In spite of this impressive record and a large invested base, we are on the threshold of a major disruption in the television industry. After fifty years of continuous refinement, the underlying technology of television is going to be entirely redone. Digital video is already proliferating in a variety of applications such as video‐conferencing, multimedia computing, and program production; the impediments that have held it back are rapidly disappearing. The key enabling technologies are (
1
) mature and standardized algorithms for high‐quality compression; (
2
) inexpensive and powerful integrated circuits for processing, storing, and reconstructing video signals; (
3
) inexpensive, high‐capacity networks for transporting video; (
4
) uniform methods for storing, addressing, and accessing multimedia content; and (
5
) evolution of computer architecture to support video I/O. The market drivers include: (
1
) direct consumer access for content providers, (
2
) convergence of video with other information sources such as print; (
3
) the emergence of a fast growing consumer market for personal computing, (
4
) the evolution of the Internet and other networks in the commercial domain, and (
5
) the removal of various regulatory barriers.

This article deals with the technology of digital television. This articles starts with the way the television signal is sampled (scanning) and digitized. A discussion of techniques of compression to reduce the bit rate to a manageable level is given. The emerging standards for compression is described.
Gravure Multi‐Copy Printing
Authors: Lee Barry
Published: October 2003

Gravure
, also known as
rotogravure
, is an
intaglio
(from the Italian word “intagliare” meaning to engrave) printing process. The intaglio printing processes are characterized by printing plates (image carriers) images with have been etched or engraved into a hard surface. To print from an intaglio image carrier, the recessed images must be flooded, or filled with ink and the surface of the image carrier must be cleared of ink, usually by a metal wiping blade known as a “doctor blade.” The paper or other substrate is pressed against the intaglio image carrier, and the resulting contact between substrate and ink‐filled image areas causes the ink to transfer from the image carrier to the substrate.

Gravure printing has evolved from early intaglio printing processes, and has been adapted to a rotary printing process capable of higher resolution, higher speeds, and greater production capacity than the traditional intaglio processes. The primary differences between gravure and printing from a conventional intaglio plate involve the type of ink used for each process and the variation of the image carrier.

The gravure printing process utilize much more fluid, low viscosity ink. This ink has been adapted to dry quickly on a variety of substrates. The gravure printing process is currently the third most common process used in the United States and the second most commonly used process in Europe and Asia. Three distinctly different market segments use the gravure process: publication, packaging, and specialty. Gravure printed publication products include magazines, Sunday newspaper supplements, catalogs and newspaper advertising inserts. Gravure packaging presses are designed to handle the specific substrates used in the packaging industry. Gravure‐printed packaging products include folding cartons, usually printed on paperboard, flexible packaging, usually printed on polyethylene or polypropylene, and labels and wrappers. The most interesting and diverse segment of gravure printing is known as the product or specialty segment e.g., wallcoverings, gift wrap, vinyl flooring, etc. The strength of gravure derives from the simplicity of operation—fewer moving parts. This allows for a more stable and consistent production process.
Image Formation
Authors: Hornak Joseph P.
Published: October 2003

An imaging system consists of ten loosely defined components or subsystems: the imaged object, probing radiation, measurable property, image formation, detected radiation, detector, processing, storage, display, and end user subsystems. The image formation subsystem maps spectroscopic information from the imaged object, person, or phenomenon onto a detector so that the processing subsystem can create an image. In one of the simplest optical systems, a camera, the image formation component is a lens, the spectroscopic property is the reflected light from the imaged object, and the detector is a sheet of photographic film.

There are seven general classes of image formation techniques: optical, tomographic, holographic, scanning, triangulation, projection, and hybrid. Optical techniques are the most common, perhaps because they are based on the first imaging system, the animal eye. Current optical imaging systems use lenses, mirrors, and waveguides. Tomographic techniques produce images of a thin slice through an object. They are used for clinical and nondestructive analysis. Magnetic resonance imaging (MRI), ultrasound imaging, and computed tomographic imaging are a few examples of systems that use tomographic image formation techniques. Holographic techniques produce three‐dimensional images based on the interference patterns between light waves from the imaged object and a reference. This article focuses on image formation techniques based on scanning, triangulation, projection, and combinations of the others (hybrid).
Image Quality Metrics
Authors: Burningham Norman , Pizlo Zygmunt , Allebach Jan P.
Published: October 2003

Images produced on monitors, printers, copiers, and films contain a variety of elements, including text, graphics, and pictorial segments. As viewers evaluate the quality of images, they may notice that various image elements are not well formed or do not communicate the desired intent. Examples of some of the most significant deficiencies seen in images that have pictorial segments include lack of clarity in details, noise in areas expected to be smooth, loss of information in highlights or darker areas, and inaccurate representation of color. These characteristics form the basis for defining sharpness, graininess, tone scale, and color rendition, respectively. These four attributes are significant factors that viewers consider when judging image quality. In images containing text and graphics, perception of quality is critically affected by roughness of edges or lines that should be smooth, blurred edges, or nonuniform density. These defects in image rendering.

In addition to the imperfections described, artifacts are often introduced into the images because of mechanical or material problems during imaging.

In this article, physical and perceptual aspects of image quality are discussed. Objective methods, which relate the design parameters to the physical parameters of the image are reviewed. Psychophysical methods that are used to characterize the percept in terms of the underlying perceptual or physical scale are then reviewed. Finally, the problem of formulating and validating computational models of image fidelity is discussed.
Over the Horizon (OTH) Radar
Authors: Anderson S. J. , Barnes R. I. , Colegrove S. B. , Earl G. F. , Sinnott D. H.
Published: October 2003

In this article starts with a description of over‐the‐horizon radar in general terms and current implementations. Subsequent sections expand in more detail on propagation and scattering issues, OTHR in operation (includes discrete target surveillance and monitoring, and geophysical sensing operations) and system implementation (includes subsystem hardware design, signal processing, and limitations).
Scanning Electrochemical Microscopy
Authors: Wipf David O.
Published: October 2003

Scanning electrochemical microscopy (SECM) is one of a number of scanned probe microscopy (SPM) techniques invented following the demonstration of the scanning tunneling microscope. The use of an electrochemical process for image formation defines SECM. In most applications of the method, an ultramicroelectrode (UME) is used as the probe and the probe signal is the Faradic current arising from the electrolysis of solution species. In other cases, the use of an ion‐selective electrode (ISE) as the probe provides a probe signal proportional to the logarithm of the activity of an ion in solution (eg., pH). In SECM, the primary interaction between probe tip and sample is mediated by diffusion of solution species between the sample and the tip of the probe, which distinguishes SECM from other SPM methods that may use an electrochemically active probe. An electrochemically active probe permits a versatile range of experiments, an essential aspect of which is chemical sensitivity or control of chemical processes occurring at a substrate surface.

Forming an image in an SPM technique requires that the probe signal be perturbed in a reproducible fashion by some aspect of the imaged substrate. There are two principal image‐forming modes in SECM: feedback and generation/collection (GC). The feedback mode uses the Faradaic current that flows from electrolysis of an intentionally‐added or naturally present mediator species at an UME probe.

Imaging in the feedback mode provides topographic images of blocking or conducting surfaces. Images of many types of surfaces have been obtained in the feedback mode; examples include images of electrodes, polymer films, and immiscible liquid interfaces.

It is possible to manipulate the SECM imaging conditions to produce images that representing chemical and electrochemical activity.

The generation/collection (GC) mode uses the probe to detect changes in the concentration of a chemical species at the surface of the imaged material. Ideally, the probe acts as a passive sensor to produce concentration maps of a particular chemical species near the substrate surface. GC mode imaging is described further by the type of sensing probe used. In amperometric GC imaging, the probe is an UME, which detects species by electrolysis. First reported as a method to map electrochemically active areas on electrodes, amperometric GC is used to make high‐resolution chemical concentration maps of corroding metal surfaces, biological materials, and polymeric materials. In addition, measurements of ion fluxes through porous materials, such as skin and dental material, are useful applications. In potentiometric GC imaging, the probe is an ISE, which has the advantage of increased sensitivity to nonelectroactive ions and improved selectivity for imaging a desired ion concentration.