scispace - formally typeset
Search or ask a question
Author

David Spiegel

Bio: David Spiegel is an academic researcher from Stanford University. The author has contributed to research in topics: Medicine & Breast cancer. The author has an hindex of 106, co-authored 733 publications receiving 46276 citations. Previous affiliations of David Spiegel include Tel Aviv University & University of Adelaide.


Papers
More filters
Posted ContentDOI
21 Mar 2023-bioRxiv
TL;DR: In this paper , a synthesis of the late summer mixed layer food web in the Northeast Pacific was extensively characterized during the 2018 EXport Processes in the Ocean from Remote Sensing (EXPORTS) field campaign at the long-running time-series site, Ocean Station Papa.
Abstract: Food webs trace the flow of organic matter and energy among producers and consumers; for pelagic marine food webs, network complexity directly influences the amount and form of carbon exported to the deep ocean via the biological pump. Here we present a synoptic view of mixed layer food web dynamics observed during the late summer 2018 EXport Processes in the Ocean from Remote Sensing (EXPORTS) field campaign in the subarctic Northeast Pacific at the long-running time-series site, Ocean Station Papa. Carbon biomass reservoirs of phytoplankton, microzooplankton, and bacterioplankton, were approximately equal while mesozooplankton biomass was 70% lower. Live organisms composed ∼40% of the total particulate organic carbon within the mixed layer: the remainder was attributed to detritus. Rates of carbon transfer among reservoirs indicated production and assimilation rates were well balanced by losses, leaving little organic carbon available for export. The slight positive net community production rate generated organic carbon that was exported from the system in the form of food web byproducts, such as large fecal pellets generated by mesozooplankton. This characteristically regenerative food web had relatively slow turnover times with small-magnitude transfers of carbon relative to standing stocks that occurred amidst a high background concentration of detrital particles and dissolved organic matter. The concurrent estimation of food web components and rates revealed that separated processes dominated the transfer of carbon within the food web compared to those that contributed to export. Plain Language Summary The biological carbon pump drives a downward flux of organic matter from the sunlit surface ocean to the vast ocean interior. Ecological interactions in the surface ocean directly affect the amount and type of carbon that is exported to the deep ocean. In this study, we present a synthesis of the late summer mixed layer food web in the Northeast Pacific that was extensively characterized during the 2018 EXport Processes in the Ocean from Remote Sensing (EXPORTS) field campaign. We found the majority of carbon was recycled within the mixed layer by microbes through multiple transfers between producers and consumers. Larger organisms, mesozooplankton and salps, only consumed a small amount of carbon but through the formation of sinking fecal pellets were the main mechanism of transporting carbon out of the system. The study highlights the need to concurrently study microbial and large organism dynamics to develop a predictive understanding of the fate of organic carbon in the oceans. Key Points The microbial loop dominated carbon flow in the late summer mixed layer food web of the North Pacific, most net production was respired leaving little carbon available for export. Active production and consumption of organic carbon occurred amid a high background of detrital particulate organic carbon (58% of total) with slow turnover time, 66 d. Mesozooplankton which had relatively minor carbon consumption rates created the majority of export production due to efficient repackaging of consumed material.

2 citations

Book ChapterDOI
01 Jan 2002

2 citations

Journal ArticleDOI
TL;DR: Clinicians should also be mindful that the dialysis procedure itself exposes patients to potential toxins, and efforts to minimize these risks should be stressed.

2 citations

Journal ArticleDOI
TL;DR: All that Kirsch and colleagues are harping on is that a formal hypnotic induction is not needed to elicit hypnotic response among hypnotizable people, why results are often comparable when hypnotic suggestions are given with and without a formal induction.
Abstract: All that Kirsch and colleagues are harping on is that a formal hypnotic induction is not needed to elicit hypnotic response among hypnotizable people. That is why results are often comparable when hypnotic suggestions are given with and without a formal induction. Furthermore, many of the so-called ‘nonstate’ studies do not take hypnotizability into account. Differences of any kind, with or without a hypnotic induction, are unlikely to emerge among people who are not at least somewhat hypnotizable. It may indeed be the case that many people are not aware of slipping in and out of hypnotic states because it is such a natural shift in consciousness among those with the capacity. People do so spontaneously during intense experiences of absorption (Tellegen and Atkinson, 1974; Tellegen, 1981), traumatic stress (Spiegel, 1991; Spiegel, 2001; Butler, Duran, et al., 1996), or ‘flow.’ (Csikszentmihalyi, 1991; Csikszentmihalyi, 1997). Those with the ability may not identify it as particularly unusual because it is part of their routine cognitiveexperiential landscape. From the article: “When controlling for the effect of nonhypnotic suggestion, it is crucial that the exact same suggestion is given in both the hypnotic and nonhypnotic conditions. People can be remarkably sensitive to the wording of imaginative suggestions. If the wording is not the same in both conditions (e.g., Kosslyn, Thompson, et al., 2000; Iani, Ricci, et al., 2006), it can confound the nature of the induction of hypnosis and the nature of the suggestion. With such ambiguity, it is impossible to know whether differences in response are due to hypnosis or to differences in the wording of the suggestion.” Talk about ambiguity – I cannot make sense of the meaning of this paragraph, especially as a co-author of the Kosslyn et al. study. By definition, the

2 citations

Journal ArticleDOI
TL;DR: In this article , the authors evaluated the use of Ki-67 testing and treatment patterns in patients with HR+, human epidermal growth factor receptor 2-negative early breast cancer.
Abstract: The National Comprehensive Cancer Network recommends that patients with hormone receptor-positive early breast cancer be considered for adjuvant endocrine therapy (ET) after primary treatment like surgical excision. Adjuvant chemotherapy (CT) use primarily depends on risk of recurrence. Biomarkers such as Ki-67 potentially have most value in patients with intermediate risk factors, such as involvement of 1-3 positive nodes. This study evaluated the use of Ki-67 testing and treatment patterns in patients with HR+, human epidermal growth factor receptor 2-negative early breast cancer.This was an observational retrospective cohort study of patients with electronic medical records from January 2010 to August 2018 treated for HR+, HER2- early breast cancer at Sarah Cannon sites in the United States (US). Overall, 567 patients were randomly selected after using the eligibility criteria: female or male ≥18 years, without distant metastases, and with available physician and pathology reports. Multivariable logistic regression was used to investigate factors predicting Ki-67 testing and test results. Descriptive analyses were applied to treatment patterns.Multivariable logistic regression analyses found no clinical or pathological factors that predicted whether Ki-67 testing had been ordered by physicians. Of all tested patients (N = 130), having Grade-2 tumors (OR, 7.95 [95% CI: 2.05, 30.9]; p = 0.0027) or Grade-3 tumors (OR, 95.3 [95% CI, 11.9, 760.7]; p < 0.001) at initial diagnosis was a predictor of high Ki-67 expression (≥20%). Ki-67 expression was tested in 23.6% (61/258) of patients with 1-3 positive nodes; 54.1% of them (33/61) had high Ki-67 expression (≥20%). While having a higher grade tumor predicted high Ki-67 (≥20%), 28.6% of patients with Grade-1 tumors also had high Ki-67 expression. Neo-adjuvant therapy was received by 16.0% of patients (91/567), most of whom (66/91; 72.5%) received CT alone. Adjuvant therapy, either endocrine and/or chemotherapy, was received by 92.6% (525/567) of patients and by 67.0% (61/91) of those who received neo-adjuvant therapy. Most (428/525, 81.5%) received ET in the adjuvant treatment setting.High grade tumors predicted high Ki-67 (≥20%) expression, but Ki-67 testing was not widely used in these US patients. Most HR+, HER2- early breast cancers were treated with adjuvant ET, with or without CT.

2 citations


Cited by
More filters
28 Jul 2005
TL;DR: PfPMP1)与感染红细胞、树突状组胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作�ly.
Abstract: 抗原变异可使得多种致病微生物易于逃避宿主免疫应答。表达在感染红细胞表面的恶性疟原虫红细胞表面蛋白1(PfPMP1)与感染红细胞、内皮细胞、树突状细胞以及胎盘的单个或多个受体作用,在黏附及免疫逃避中起关键的作用。每个单倍体基因组var基因家族编码约60种成员,通过启动转录不同的var基因变异体为抗原变异提供了分子基础。

18,940 citations

Journal ArticleDOI
TL;DR: Correlational, quasi-experimental, and laboratory studies show that the MAAS measures a unique quality of consciousness that is related to a variety of well-being constructs, that differentiates mindfulness practitioners from others, and that is associated with enhanced self-awareness.
Abstract: Mindfulness is an attribute of consciousness long believed to promote well-being. This research provides a theoretical and empirical examination of the role of mindfulness in psychological well-being. The development and psychometric properties of the dispositional Mindful Attention Awareness Scale (MAAS) are described. Correlational, quasi-experimental, and laboratory studies then show that the MAAS measures a unique quality of consciousness that is related to a variety of well-being constructs, that differentiates mindfulness practitioners from others, and that is associated with enhanced selfawareness. An experience-sampling study shows that both dispositional and state mindfulness predict self-regulated behavior and positive emotional states. Finally, a clinical intervention study with cancer patients demonstrates that increases in mindfulness over time relate to declines in mood disturbance and stress. Many philosophical, spiritual, and psychological traditions emphasize the importance of the quality of consciousness for the maintenance and enhancement of well-being (Wilber, 2000). Despite this, it is easy to overlook the importance of consciousness in human well-being because almost everyone exercises its primary capacities, that is, attention and awareness. Indeed, the relation between qualities of consciousness and well-being has received little empirical attention. One attribute of consciousness that has been much-discussed in relation to well-being is mindfulness. The concept of mindfulness has roots in Buddhist and other contemplative traditions where conscious attention and awareness are actively cultivated. It is most commonly defined as the state of being attentive to and aware of what is taking place in the present. For example, Nyanaponika Thera (1972) called mindfulness “the clear and single-minded awareness of what actually happens to us and in us at the successive moments of perception” (p. 5). Hanh (1976) similarly defined mindfulness as “keeping one’s consciousness alive to the present reality” (p. 11). Recent research has shown that the enhancement of mindfulness through training facilitates a variety of well-being outcomes (e.g., Kabat-Zinn, 1990). To date, however, there has been little work examining this attribute as a naturally occurring characteristic. Recognizing that most everyone has the capacity to attend and to be aware, we nonetheless assume (a) that individuals differ in their propensity or willingness to be aware and to sustain attention to what is occurring in the present and (b) that this mindful capacity varies within persons, because it can be sharpened or dulled by a variety of factors. The intent of the present research is to reliably identify these inter- and intrapersonal variations in mindfulness, establish their relations to other relevant psychological constructs, and demonstrate their importance to a variety of forms of psychological well-being.

9,818 citations

01 Jan 2014
TL;DR: These standards of care are intended to provide clinicians, patients, researchers, payors, and other interested individuals with the components of diabetes care, treatment goals, and tools to evaluate the quality of care.
Abstract: XI. STRATEGIES FOR IMPROVING DIABETES CARE D iabetes is a chronic illness that requires continuing medical care and patient self-management education to prevent acute complications and to reduce the risk of long-term complications. Diabetes care is complex and requires that many issues, beyond glycemic control, be addressed. A large body of evidence exists that supports a range of interventions to improve diabetes outcomes. These standards of care are intended to provide clinicians, patients, researchers, payors, and other interested individuals with the components of diabetes care, treatment goals, and tools to evaluate the quality of care. While individual preferences, comorbidities, and other patient factors may require modification of goals, targets that are desirable for most patients with diabetes are provided. These standards are not intended to preclude more extensive evaluation and management of the patient by other specialists as needed. For more detailed information, refer to Bode (Ed.): Medical Management of Type 1 Diabetes (1), Burant (Ed): Medical Management of Type 2 Diabetes (2), and Klingensmith (Ed): Intensive Diabetes Management (3). The recommendations included are diagnostic and therapeutic actions that are known or believed to favorably affect health outcomes of patients with diabetes. A grading system (Table 1), developed by the American Diabetes Association (ADA) and modeled after existing methods, was utilized to clarify and codify the evidence that forms the basis for the recommendations. The level of evidence that supports each recommendation is listed after each recommendation using the letters A, B, C, or E.

9,618 citations

Journal ArticleDOI
TL;DR: The following Clinical Practice Guidelines will give up-to-date advice for the clinical management of patients with hepatocellular carcinoma, as well as providing an in-depth review of all the relevant data leading to the conclusions herein.

7,851 citations