Social media influences National Park visitation.

Visitation to National Parks in the United States increased by more than 25% since 2010, rising from roughly 70 to 90 million annual visitors. Anecdotes suggest that this increase was driven by the advent of social media in the early-to-mid 2010s, generating a new form of exposure for parks, and has led to concerns about overcrowding and degradation of environmental quality. However, there is little empirical evidence on the role of social media in influencing recreation decisions. Here, I construct a dataset on social media exposure (SME) for each National Park and relate that exposure to changes in visitation over the last two decades. High SME parks see visitation increase by 16 to 22% relative to parks with less exposure, which comes with a concomitant increase in revenue. Low SME parks have no, or negative, changes in visitation. These estimates account for unobserved park heterogeneity and are based on an instrumental variables strategy that predicts exposure with a park's online popularity prior to the social media era. Additional analysis suggests that recent social media posts that include media attachments increase visitation, while posts with negative sentiment reduce visitation. These results provide insight for the National Park Service-which faces more than $22 billion in deferred maintenance costs and is considering policy options to manage demand-as well as for management of recreation on other public lands.

Assessing effective radiative forcing from aerosol-cloud interactions over the global ocean.

How clouds respond to anthropogenic sulfate aerosols is one of the largest sources of uncertainty in the radiative forcing of climate over the industrial era. This uncertainty limits our ability to predict equilibrium climate sensitivity (ECS)-the equilibrium global warming following a doubling of atmospheric CO2. Here, we use satellite observations to quantify relationships between sulfate aerosols and low-level clouds while carefully controlling for meteorology. We then combine the relationships with estimates of the change in sulfate concentration since about 1850 to constrain the associated radiative forcing. We estimate that the cloud-mediated radiative forcing from anthropogenic sulfate aerosols is [Formula: see text] W m-2 over the global ocean (95% confidence). This constraint implies that ECS is likely between 2.9 and 4.5 K (66% confidence). Our results indicate that aerosol forcing is less uncertain and ECS is probably larger than the ranges proposed by recent climate assessments.

A risk-reward examination of sample multiplexing reagents for single cell RNA-Seq.

Single-cell RNA sequencing (scRNA-Seq) has emerged as a powerful tool for understanding cellular heterogeneity and function. However the choice of sample multiplexing reagents can impact data quality and experimental outcomes. In this study, we compared various multiplexing reagents, including MULTI-Seq, Hashtag antibody, and CellPlex, across diverse sample types such as human peripheral blood mononuclear cells (PBMCs), mouse embryonic brain and patient-derived xenografts (PDXs). We found that all multiplexing reagents worked well in cell types robust to ex vivo manipulation but suffered from signal-to-noise issues in more delicate sample types. We compared multiple demultiplexing algorithms which differed in performance depending on data quality. We find that minor improvements to laboratory workflows such as titration and rapid processing are critical to optimal performance. We also compared the performance of fixed scRNA-Seq kits and highlight the advantages of the Parse Biosciences kit for fragile samples. Highly multiplexed scRNA-Seq experiments require more sequencing resources, therefore we evaluated CRISPR-based destruction of non-informative genes to enhance sequencing value. Our comprehensive analysis provides insights into the selection of appropriate sample multiplexing reagents and protocols for scRNA-Seq experiments, facilitating more accurate and cost-effective studies.

Characterizing the Immune Environment in Peritoneal Carcinomatosis: Insights for Novel Immunotherapy Strategies.

BACKGROUND OR PURPOSE: Carcinomatosis, a distinct pattern of metastatic cancer in the peritoneal cavity, poses challenges for treatment and has limited therapeutic options. Understanding the immune environment of peritoneal surface malignancies is crucial for developing effective immunotherapeutic approaches. This study characterizes soluble immune mediators in the peritoneal fluid of patients with and without carcinomatosis to identify targets for novel treatment strategies. PATIENTS AND METHODS: Serum and peritoneal fluid samples were collected from surgical patients, and a multianalyte analysis was performed using the Luminex platform. Patient characteristics, tumor sites, and sample collection details were recorded. Soluble immune mediator levels were measured and compared between peritoneal fluid and serum samples and among clinical subgroups. Statistical analysis was conducted to assess differences in analyte concentrations and correlations between samples. RESULTS: There were 39 patients included in the study, with varying surgical indications. Significant differences were observed in soluble immune mediator levels between peritoneal fluid and serum, with peritoneal fluid exhibiting lower concentrations. Carcinomatosis was associated with elevated levels of proinflammatory mediators, including IL-6 and IL-8, while adaptive immune response markers were low in peritoneal fluid. CONCLUSIONS: The peritoneal immune microenvironment in carcinomatosis favors innate immunity, presenting a challenging environment for effective antitumor response. High levels of proinflammatory mediators suggest potential targets for intervention, such as the IL-6 axis, FGF2, IL-8, and CCL2; these could be explored as potential mitigators of malignant ascites and enhance anti-tumor immune responses. These findings provide valuable insights for developing immunotherapy strategies and improving outcomes in patients with peritoneal carcinomatosis.

Deprescribing bisphosphonates for older adults with dementia: perspectives of caregivers.

Little is known about caregivers' perspectives on deprescribing bisphosphonates for older adults with dementia. Caregivers agreed that fracture prevention was important for maintaining functional independence but acknowledged that changing goals of care may justify deprescribing. Conversations grounded in "what matters most" can align fracture prevention treatment with goals of care. PURPOSE: The long-term fracture prevention benefits of bisphosphonates may begin to be overshadowed by the potential burden of adverse effects and polypharmacy for older adults living with dementia as the disease progresses. We characterized factors that influence caregiver decision-making for continuing versus deprescribing bisphosphonates for persons living with dementia. METHODS: We conducted 11 interviews with family or informal caregivers of older adults living with dementia in the community or in long-term care who had been treated with bisphosphonates. Interviews focused on experiences caring for someone who has experienced a fracture, perceived benefits and harms of bisphosphonates, and experiences with deprescribing. Analyses were conducted using a qualitative framework methodology guided by the Health Belief Model. RESULTS: Most caregivers were male (n = 8), younger than 65 (n = 8) and were an adult child caregiver (n = 8). Three caregivers were Black and five were Latino/a. Attempts to maintain functional independence despite high likelihood of falls was frequently discussed as contributing to fracture risk, in this population. Many caregivers perceived fracture prevention treatment as important, while several noted that it may become less important near the end of life. Perceived benefits of fracture prevention treatment for persons with dementia included improved quality of life and maintaining independence. Although most indicated that bisphosphonates were well tolerated, gastrointestinal adverse effects, preference for fewer treatments, and dementia-related behaviors that interfere with medication administration may be reasons for deprescribing. CONCLUSION: Conversations grounded in caregiver experiences and "what matters most" may help optimize fracture prevention treatment for older adults with dementia.

Speckle-free coherent imaging through deep turbulence.

We develop and validate a model-based iterative reconstruction framework for digitally correcting coherent images corrupted by deep turbulence. In general, this framework is applicable to coherent-imaging approaches that gain access to the complex-optical field; however, we demonstrate our approach with multi-shot digital holography data. To test our image correction framework, we generate calibrated deep-turbulence conditions from our laboratory testbed. Using the resulting data, we demonstrate groundbreaking performance in terms of speckle-free image correction in deep-turbulence conditions.

Primary adrenal sarcomas: A national analysis of epidemiological trends, treatment patterns, and outcomes.

BACKGROUND AND OBJECTIVES: Primary adrenal sarcoma (PAS) is an exceedingly rare malignancy with limited data available on its epidemiology, management, and outcomes. This study aimed to characterize the national incidence, treatment patterns, and survival of PAS utilizing a National Cancer Database. METHODS: The National Cancer Database was queried for patients diagnosed with primary adrenal tumors from 2004 to 2019. Cases with sarcoma histology were identified as PAS. Annual incidence trends, histological distribution, treatment modalities (surgery, chemotherapy, radiation therapy), perioperative outcomes, and overall survival (OS) were analyzed. RESULTS: Of 7213 primary adrenal tumor cases, 332 (4.6%) were PAS. The most common histological subtypes were leiomyosarcoma (37.3%), hemangiosarcoma (27.1%), and sarcoma not otherwise specified (6.0%). Most cases (71.7%) presented as locoregional disease. Treatment included surgery alone (47.8%), surgery plus chemotherapy and/or radiation (27.1%), chemotherapy/radiation alone (13.3%), or no treatment (13.9%). For surgical cases, the median length of stay was 5 days, the 30-day readmission rate was 3.36%, and the 30/90-day mortality rates were 3.65% and 9.90%, respectively. The 5-year OS rate for surgery alone was 43%, with a median OS of 34.6 months. For surgery with radiation/chemotherapy, the 5-year OS rate was 37.3%, with a median OS of 35.4 months. CONCLUSIONS: This largest analysis of PAS to date demonstrates that most cases present as locoregional disease amenable to surgical resection, with favorable outcomes. The role of adjuvant therapy remains unclear, as no significant survival difference was observed between surgery alone and multimodal treatment.

Long-term patient-reported values following cancer surgery: A global survey study.

BACKGROUND AND OBJECTIVES: We evaluated the long-term quality of life (QOL) and priorities of an international cohort of cancer surgery survivors. METHODS: Patients were surveyed through online support groups. We utilized the Short Form-12 questionnaire to evaluate QOL and a novel survey to assess the relative importance of longevity, experience, and costs. RESULTS: A total of 592 patients from six continents responded. They were 58 ± 12 years old, 70% female, and 92% White. Patients averaged 37 months from their initial cancer diagnosis, with a maximum survivorship of 46 years. Across 17 disease sites, respondents generally ranked longevity, functional independence, and emotional well-being most important, while treatment experience and costs were ranked least important (W = 33.6%, p < 0.001). However, a subset of respondents ranked costs as significantly important. There were no differences in QOL based on demographics, except patients with higher education and income reported better QOL scores. Despite improvements in QOL throughout survivorship, both physical-QOL (41.1 ± 11.1 at 1 year vs. 42.3 ± 12.6 at 5 years, p = 0.511) and mental-QOL (41.3 ± 13.4 at 1 year vs. 44.6 ± 13.9 at 5 years, p = 0.039) remained below that of the general population (50 ± 10; both p < 0.001). CONCLUSIONS: Cancer survivors experience enduring physical and mental impairment throughout survivorship. Future efforts should aim to provide sustained support across varied socioeconomic groups, ensuring equitable care and enhancement of QOL postcancer treatment.

Genetic Predisposition to Sarcoma: What Should Clinicians Know?

OPINION STATEMENT: Pathogenic germline variants in the setting of several associated cancer predisposition syndromes (CPS) may lead to the development of sarcoma. We would consider testing for a CPS in patients with a strong family history of cancer, multiple primary malignancies, and/or pediatric/adolescent/young adult patients diagnosed with other malignancies strongly associated with CPS. When a CPS is diagnosed in a patient with sarcoma, additional treatment considerations and imaging options for those patients are required. This applies particularly to the use of radiation therapy, ionizing radiation with diagnostic imaging, and the use of alkylating chemotherapy. As data and guidelines are currently lacking for many of these scenarios, we have adopted a shared decision-making process with patients and their families. If the best chance for cure in a patient with CPS requires utilization of radiation therapy or alkylating chemotherapy, we discuss the risks with the patient but do not omit these modalities. However, if there are treatment options that yield equivalent survival rates, yet avoid these modalities, we elect for those options. Considering staging imaging and post-therapy evaluation for sarcoma recurrence, we avoid surveillance techniques that utilize ionizing radiation when possible but do not completely omit them when their use is indicated.

Leaning in and moving forward: a call to action and review of diversity initiatives in SAGES.

BACKGROUND: Diversity, equity, and inclusion have been an intentional focus for SAGES well before the COVID-19 pandemic and the coincident societal recognition of social injustices and racism. Longstanding inequities within our society, healthcare, and the surgery profession have come to light in the aftermath of events that rose to attention around the time of Covid. In so doing, they have brought into focus disparities, injustices, and inequalities that have long been present in the field of surgery, selectively affecting the most vulnerable. METHODS: This White paper examines the current state of diversity within the field of surgery and SAGES (Society of American Gastrointestinal and Endoscopic Surgeons) approach and effort to pave the way forward to meaningful change. We delineate the imperative for diversity, equity, and inclusion for all. By all, we mean to be inclusive of the diversity of gender and sexual orientation, race, ethnicity, geography, sex, and disability in the field of surgery. RESULTS: SAGES is an organization that lives at the intersection of education and innovation. It has a vital role in assisting the surgical profession in addressing these issues and needs and being a force alongside others for sustained and necessary change. SAGES can only realize these goals through a commitment across all aspects of the organization to embed diversity, equity, and inclusion into our very fabric. CONCLUSION: True diversity, equity, and inclusion within a surgical organization is vital for its longevity, growth, relevance, and impact. Unfortunately, the absence of DEI limits opportunity, robs the organization of collective intelligence in an environment in which its presence is critical, contributes to health inequities, and impoverishes all within the society and its value to all with whom it interfaces. SAGES is an organization that lives at the intersection of education and innovation. It has a vital role in assisting the surgical profession in addressing these issues and needs and being a force alongside others for sustained and necessary change. SAGES can only realize these goals through a commitment across all aspects of the organization to embed diversity, equity, and inclusion into our very fabric. Strategies like those highlighted in this White Paper, may be within our grasp and we can learn yet more if we remain in a place of humility and teachability in the future.

Perception of uncontrollable mortality risk is associated with food insecurity and reduced economic effort among resource-insecure college students during COVID-19.

In the framework of the uncontrollable mortality risk hypothesis, resource scarcity intersects with mortality risk, shaping resource allocation strategies with enduring impacts on human health and wellbeing. Despite rising economic and food insecurity among US college students, little is known about how these insecurities relate to mortality risk, or how scarcity and mortality risk interact to shape college students' resource allocation strategies. We examine perceptions of resource scarcity and mortality risk and their associations with food insecurity and resource allocation strategies among economically insecure college students during COVID-19 lockdowns. Participants were recruited through an economic crisis response center at a major public university in the United States. A total of 118 participants completed an online Qualtrics survey assessing sociodemographic characteristics, perceptions of mortality risk and resource availability, food security, economic effort, and time perspective; a subset (n = 51) also participated in a telephone interview assessing psychological distress. In general, participants reported more environmental adversity and economic effort during COVID-19 lockdowns compared to before. Students experiencing higher levels of uncontrollable (and not controllable) mortality risk report lower levels of economic effort, and the association was strongest among students perceiving the fewest resources. We also found significant associations between uncontrollable mortality risk and food insecurity. Our results highlight uncontrollable mortality risk's influence on human well-being. Public health efforts should target the experiences and root structural causes of uncontrollable mortality risk, which among economically insecure college students increasingly involves food insecurity.

Investigating the linkages between food insecurity, psychological distress, and poor sleep outcomes among U.S. college students.

OBJECTIVE: Research overwhelmingly demonstrates that sleep is key to human health and wellbeing. Several factors likely contribute to sleep quality, including factors, such as food security and low income. In addition, exposure to structural inequalities early in life likely have downstream effects upon multiple dimensions of health. The objective of this study is to fill gaps in literature by specifically examining the associations between childhood food insecurity, current food insecurity, psychological distress, and sleep among college students. METHODS: QR codes were randomly distributed to students, linking them to an online quantitative survey. The survey measured sociodemographic variables, food security (current and childhood), diet, mental distress, and sleep quality. A total of n = 134 completed the entire survey. Data were analyzed using binary and multiple linear regressions, as well as cross-tabulations. RESULTS: The findings revealed that psychological distress was the primary factor influencing sleep health (𝛽 = 1.51, p < .01). Students reporting higher childhood food insecurity were more likely to experience extreme psychological distress (OR = 4.61), food insecurity in college (OR = 8.41), and lack of stable housing (OR = 5.86). CONCLUSION: This study demonstrates that potential linkages exist between childhood food insecurity, poor sleep, and greater psychological distress. While acknowledging the contribution of other factors, the study highlights the importance of addressing food insecurity in relation to sleep health, considering the significant impact of sleep to overall health and wellbeing.

CPA toxicity screening of cryoprotective solutions in rat hearts.

In clinical practice, donor hearts are transported on ice prior to transplant and discarded if cold ischemia time exceeds ∼5 h. Methods to extend these preservation times are critically needed, and ideally, this storage time would extend indefinitely, enabling improved donor-to-patient matching, organ utilization, and immune tolerance induction protocols. Previously, we demonstrated successful vitrification and rewarming of whole rat hearts without ice formation by perfusion-loading a cryoprotective agent (CPA) solution prior to vitrification. However, these hearts did not recover any beating even in controls with CPA loading/unloading alone, which points to the chemical toxicity of the cryoprotective solution (VS55 in Euro-Collins carrier solution) as the likely culprit. To address this, we compared the toxicity of another established CPA cocktail (VEG) to VS55 using ex situ rat heart perfusion. The CPA exposure time was 150 min, and the normothermic assessment time was 60 min. Using Celsior as the carrier, we observed partial recovery of function (atria-only beating) for both VS55 and VEG. Upon further analysis, we found that the VEG CPA cocktail resulted in 50 % lower LDH release than VS55 (N = 4, p = 0.017), suggesting VEG has lower toxicity than VS55. Celsior was a better carrier solution than alternatives such as UW, as CPA + Celsior-treated hearts spent less time in cardiac arrest (N = 4, p = 0.029). While we showed substantial improvement in cardiac function after exposure to vitrifiable concentrations of CPA by improving both the CPA and carrier solution formulation, further improvements will be required before we achieve healthy cryopreserved organs for transplant.

General skills amidst the details: alternative learning objectives and a framework of competencies for human anatomy.

The field of anatomy is often seen by nonanatomists as concerned primarily with the tasks of locating, naming, and describing structures; these tasks, in turn, are often assumed to require only lower-order cognitive skills (LOCSs), i.e., the Knowledge or Comprehension levels of Bloom's taxonomy. Many nonanatomists may thus believe that studying anatomy does not develop transferable higher-order cognitive skills. Published lists of anatomy learning objectives (LOs) might reinforce this view by focusing attention on numerous details of specific structures and regions. To explore this issue further, we have analyzed the structure of published peer-reviewed LOs by characterizing their organization (single-tiered or multi-tiered), inclusion of function, use of action verbs, and dependence on or independence of context. Our results suggest that previously published LO lists, despite their value, may not fully showcase opportunities for students to develop higher-order skills. In the hope of stimulating further discussion and scholarship, we present here a two-tiered framework of human anatomy competencies, i.e., generalizable skills beyond straightforward recognition and memorization. This framework, which is intended to be both student-facing and faculty-facing, illustrates how anatomy courses may be reframed as opportunities to think critically and develop sophisticated, professionally relevant skills.NEW & NOTEWORTHY Although skilled anatomists know that anatomy is much more than memorization, nonanatomists are often unsure how to emphasize general skills and problem-solving in their teaching of the subject. Here we show how a multi-tiered approach to defining and assessing learning objectives (LOs) can reframe anatomy courses as more than long lists of structures to remember.

Do couples who play together stay together? A longitudinal dyadic examination of shared leisure, financial distress, and relationship outcomes.

We examined whether shared leisure offers protection against negative associations between financial distress and relationship quality (satisfaction and commitment) for lower- and higher-income couples. We expected husbands' and wives' reports of shared leisure would be protective of the effects of financial distress (Time 2) on relationship satisfaction (Time 3) and commitment (Time 4) for higher-income couples (but not lower-income couples). Participants were drawn from a nationally representative, longitudinal study of US newly married couples. The analytic sample included both members of 1382 different-gender couples with data across the three sampled waves of data collection. Shared leisure was largely protective of the effects of financial distress on husbands' commitment for higher-income couples. For lower-income couples, higher shared leisure exacerbated this effect. These effects were only found at extreme levels of household income and shared leisure. When considering if couples who play together stay together, our findings suggest that it can, but it is critical to understand the financial situation of the couple and the resources they may have to support shared leisure activities. Professionals working with couples should consider their financial situation when making recommendation to engage in shared leisure, such as going out for recreation.

Implementation and outcomes of a dementia-friendly training program in five hospitals.

BACKGROUND: Hospitalized patients living with dementia (PLWD) age 65+ generally experience poor outcomes. This study's purpose was to implement dementia-friendly training with staff, track patient outcomes, and implement sustainable system changes. METHODS: We conducted a prospective study in five hospitals. The hospitals adopted HealthCare Interactive's CARES® Dementia 5-Step Method for Hospitals Online Training and Certification Program . After on-line modules completion, a didactic session was offered, and a retrospective pre/post survey was completed. Patient falls, length of stay, and readmission rates were collected. RESULTS: 1,836 (41 %) staff completed the training. Positive changes in staff ratings from pre- to post- intervention were observed. Number of falls and readmissions did not change. The average number of stays per patient decreased by .24 (p=0.01). Hospitals made system changes including innovative identification for PLWD. CONCLUSIONS: Dementia-friendly hospital training is effective in improving staff recognition of the symptoms and needs of PLWD, and responding appropriately.

Assessing the long-term priorities of pancreaticoduodenectomy survivors.

BACKGROUND: This study assessed the long-term quality of life (QOL) and priorities of pancreaticoduodenectomy (PD) survivors. METHODS: Survivors were surveyed via internet-based support groups. The relative importance of longevity, experience, costs, and QOL were assessed. RESULTS: The PD cohort (n = 247, 35%) was 60 ± 12 years, 71% female, and 93% white. With moderate agreement, patients ranked survival most important, followed by functional and emotional well-being; costs and experience were least important (W = 35.7%, p < 0.001). Well-being improved throughout survivorship (P-QOL: 39 ± 12 at ≤3 mo vs 43 ± 12 at >10 y, p = 0.170; M-QOL: 38 ± 13 at ≤3 mo vs 44 ± 16 at >10 y; p = 0.015) but remained below the general population (p < 0.001). PD patients with benign diagnoses ranked functional independence as most important (2.00 ± 1.13 vs 2.63 ± 1.19, p < 0.001, W = 41.1%); PD patients with malignant diagnoses regarded overall survival most important (2.10 ± 1.20 vs 1.82 ± 1.22, p < 0.16, W = 35.1%). The mean rank order of priorities remained concordant between short-term (<1 year) and long-term (>5 years) survivors. CONCLUSION: PD survivors experience long-term mental and physical health impairments, underscoring the importance of functional and emotional support. Survivors place paramount importance on overall survival, functional independence, and emotional well-being. Cancer survivors prioritize longevity, while survivors of chronic benign conditions prioritize functional independence.

Are large language models a useful resource to address common patient concerns on hallux valgus? A readability analysis.

BACKGROUND: This study evaluates the accuracy and readability of Google, ChatGPT-3.5, and 4.0 (two versions of an artificial intelligence model) responses to common questions regarding bunion surgery. METHODS: A Google search of "bunionectomy" was performed, and the first ten questions under "People Also Ask" were recorded. ChatGPT-3.5 and 4.0 were asked these ten questions individually, and their answers were analyzed using the Flesch-Kincaid Reading Ease and Gunning-Fog Level algorithms. RESULTS: When compared to Google, ChatGPT-3.5 and 4.0 had a larger word count with 315 ± 39 words (p < .0001) and 294 ± 39 words (p < .0001), respectively. A significant difference was found between ChatGPT-3.5 and 4.0 compared to Google using Flesch-Kincaid Reading Ease (p < .0001). CONCLUSIONS: Our findings demonstrate that ChatGPT provided significantly lengthier responses than Google and there was a significant difference in reading ease. Both platforms exceeded the seventh to eighth-grade reading level of the U.S. LEVEL OF EVIDENCE: N/A.

Are Hydroxyl Radicals Spontaneously Generated in Unactivated Water Droplets?

Spontaneous ionization/breakup of water at the surface of aqueous droplets has been reported with evidence ranging from formation of hydrogen peroxide and hydroxyl radicals, indicated by ions at m/z 36 attributed to OH•-H3O+ or (H2O-OH2)+• as well as oxidation products of radical scavengers in mass spectra of water droplets formed by pneumatic nebulization. Here, aqueous droplets are formed both by nanoelectrospray, which produces highly charged nanodrops with initial diameters ~100 nm, and a vibrating mesh nebulizer, which produces 2 - 20 µm droplets that are less highly charged. The lifetimes of these droplets range from 10s of µs to 560 ms and the surface-to-volume ratios span ~100-fold range. No ions at m/z 36 are detected with pure water, nor are significant oxidation products for the two radical scavengers that were previously reported to be formed in high abundance. These and other results indicate that prior conclusions about spontaneous hydroxyl radical formation in unactivated water droplets are not supported by the evidence and that water appears to be stable at droplet surfaces over a wide range of droplet size, charge and lifetime.

Variable Mixing with Theta Emitter Mass Spectrometry: Changing Solution Flow Rates with Emitter Position.

Two solutions can be rapidly mixed using theta glass emitters, with products measured using electrospray ionization mass spectrometry. The relative flow rates of the two emitter channels can be measured using different calibration compounds in each channel, or the flow rates are often assumed to be the same. The relative flow rates of each channel can be essentially the same when the emitters are positioned directly in front of the capillary entrance of a mass spectrometer, but the relative flow rates can be varied by up to 3 orders of magnitude by moving the position of the emitter tip ±1 cm in a direction that is perpendicular to the inner divider. Results of the emitter position on the different concentrations of reagents in the initially formed electrospray droplets are demonstrated through protein denaturation using a supercharging reagent as well as two different bimolecular reactions. The average charge state of myoglobin changed from +7.8 to +13.8 when 2.5% sulfolane was mixed with a 200 mM ammonium acetate solution containing the protein when the position of the emitter was scanned in front of the mass spectrometer inlet. The conversion ratio of a bimolecular reaction was changed from 0.98 to 0.04 with varying emitter positions. These results show that the relative flow rates must be carefully monitored because the droplet composition depends strongly on the position of the theta glass emitters. This method can be used to measure the dependence of reaction kinetics on different solution concentrations by using a single emitter and only two solutions.