PSYCHOGEOGRAPHY

Living in a favela influences how people move around the city

Research using mobile phone data indicates that the living condition reduces the variability of daily movements

Fundação de Amparo à Pesquisa do Estado de São Paulo

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image: 

Sequence of inferred locations (trajectories) of mobile phone users, where each color represents a different individual. This data was used in a study examining mobility variability among São Paulo favela residents 

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Credit: Matheus Henrique Cunha Barboza

A study based on the analysis of mobile phone data reveals that residents of favelas in the city of São Paulo, Brazil, exhibit less variability in their daily travel patterns than residents of formal areas with similar incomes.

The study was published in the journal Transportation and was authored by Matheus Henrique Barboza from the Engineering School of the University of São Paulo (Poli-USP). Barboza’s work was supervised by Mariana Giannotti and co-authored by Anna Grigolon and Karst Geurs. The research is part of Barboza’s doctoral thesis developed through a dual-degree program between USP and the University of Twente in the Netherlands.

The analysis was based on 77 consecutive days of mobile phone records, totaling approximately 30 million events associated with around 6,000 users living in areas within or around São Paulo’s favelas. The study focused on intrapersonal mobility variability, or how much a person’s routes change from one workday to the next.

“Most transportation studies look at a single day in people’s lives. What we explored is the fact that phone data allows us to observe behavior over several weeks, something traditional research can’t capture,” Barboza explains.

The results show that income and living in a favela are not equivalent variables. Even after controlling for factors such as average income in the census tract, land use, employment density, and access to public transportation, the “favela” variable remained significant. In practical terms, this means that two people with similar incomes living in nearby areas may have different movement patterns simply because one of them lives in a favela.

According to Giannotti, the lower variability observed among favela residents should not be automatically interpreted as a sign of greater stability or choice. “An initial, generic hypothesis would be that favela residents face additional challenges compared to people with the same income who live in urban areas outside of favelas. Among these challenges, infrastructure bottlenecks related to mobility – such as narrow, steep alleys; distance to bus stops; and lack of adequate sidewalks – can impact access and consequently the variability of movement patterns,” she says.

The researchers used call detail records (CDRs), which are records of calls, messages, and internet connections automatically generated by cell phone operators. By identifying the antennas used over time, the researchers were able to reconstruct users’ daily movements and infer their places of residence based on their nighttime patterns.

They cross-referenced this information with data from the Demographic Census of the Brazilian Institute of Geography and Statistics (IBGE), land use databases from the City of São Paulo, and estimates of accessibility to jobs via public transportation. To measure mobility variability, the authors created a specific indicator: the total number of distinct locations among the three most frequent destinations each workday over four weeks.

Two results stand out. First, people with higher incomes tend to have less variability in their daily movements, indicating more stable routines. Second, favela residents also exhibited less variability despite being associated with more precarious economic conditions.

“Although informal workers tend to show greater variability because they work in multiple locations, living in a favela can impose additional limitations that reduce this fluctuation,” Barboza notes.

Giannotti points out that the data used in the study are from 2016 and cannot be directly extrapolated to the present. “It isn’t possible to extrapolate over time, especially considering the effects of the pandemic on people’s behavior. On the other hand, we understand that the results remain relevant from an analytical and conceptual point of view because the study investigates the mechanisms and structural relationships between mobility, income, informality, and residential status associated with more persistent characteristics of urban structures,” she says.

In addition to its academic contribution, the work has direct implications for urban planning and public policy formulation. “The research provides methods for exploring telephone data to support the development of Mobility Plans, which are mandatory for municipalities with more than 20,000 inhabitants according to the National Urban Mobility Policy,” Giannotti points out.

According to her, traditional origin and destination surveys are expensive and impractical for many municipalities. “If municipalities can advance in using this type of telephone and ticketing data for their plans, it’ll be a huge step forward in having public policies that are more data- and evidence-informed,” she says.

According to the researcher, analyses such as those carried out in the study can support policies such as ensuring adequate transportation in peripheral areas, designing fares and subsidies that align with work routines, and prioritizing infrastructure and service investments in areas with restricted daily mobility.

The data is anonymous and does not allow for direct identification of individuals. According to Barboza, access was obtained through a formal agreement with the operator. “We don’t have names, CPFs [Brazilian taxpayer identification numbers], or anything like that. What we were provided with were geographic coordinates, date, time, and an anonymized code that can’t be linked to personal information. But, of course, this is sensitive data, and therefore all use follows strict ethical protocols. The General Data Protection Law [LGPD] allows this type of research when conducted by universities and with anonymized data.”

The work was supported by FAPESP through a Doctoral Scholarship and a Research Internship Abroad Scholarship, both awarded to Barboza. It was also supported by a Research Grant to the Center for Metropolitan Studies (CEM), where Giannotti is one of the principal investigators. The CEM is one of FAPESP’s Research, Innovation, and Dissemination Centers (RIDCs).

About São Paulo Research Foundation (FAPESP)
The São Paulo Research Foundation (FAPESP) is a public institution with the mission of supporting scientific research in all fields of knowledge by awarding scholarships, fellowships and grants to investigators linked with higher education and research institutions in the State of São Paulo, Brazil. FAPESP is aware that the very best research can only be done by working with the best researchers internationally. Therefore, it has established partnerships with funding agencies, higher education, private companies, and research organizations in other countries known for the quality of their research and has been encouraging scientists funded by its grants to further develop their international collaboration. You can learn more about FAPESP at www.fapesp.br/en and visit FAPESP news agency at www.agencia.fapesp.br/en to keep updated with the latest scientific breakthroughs FAPESP helps achieve through its many programs, awards and research centers. You may also subscribe to FAPESP news agency at http://agencia.fapesp.br/subscribe.

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Journal

Transportation

DOI

10.1007/s11116-025-10695-6 

Article Title

Mobility variability of favela residents of São Paulo based on mobile phone data

 

Study finds no evidence of persistent tick-borne infection in people who link chronic illness to ticks

Accurate diagnoses are critical to the correct treatment of tick-related diseases

Norwegian University of Science and Technology

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When researchers studied Norwegians who thought tick bites caused their chronic health problems, they found no objective evidence linking the symptoms to ticks.

The same study finds that health problems reported by participants were associated with little physical activity and low labour force participation.

Many Norwegians pull ticks from their bodies every single summer. Roughly 2 per cent of those who are bitten are infected by a bacterium that leads to Lyme disease.

The disease can start with a rash that eventually spreads in the skin with a ring-shaped pattern. In some people, the disease can develop into facial paralysis, meningitis or other complications.

Can develop facial paralysis

"It is possible to get really sick from tick bites, but no matter how badly you are affected, antibiotics are the curative treatment. Most people need two weeks of treatment, while a few need up to four weeks," says Audun Olav Dahlberg.

Dahlberg is a senior consultant in clinical neurophysiology at Helse Møre og Romsdal HF, and is a specialist in clinical neurophysiology and neurology as well as a PhD research fellow at NTNU, the Norwegian University of Science and Technology.

As part of his doctoral dissertation, he examined 470 Norwegians who themselves link chronic and long-term health problems to tick bites.

His research found no evidence that the chronic health problems reported by this group are linked to ongoing tick-borne infections.

The study also shows that around 0.12 per cent of adults in Norway link chronic health problems to previous tick bites.

Depression, sick leave and exhaustion

"This is the first time that we have quantified how many people in Norway themselves link chronic health problems to tick bites. This group suffers greatly, including from a limited ability to work, severe fatigue and other health issues. Their symptoms have persisted for more than six months and they believe tick bites are the cause. However, blood tests indicate that active tick-borne infection cannot explain these persistent symptoms," says Dahlberg.

To recruit participants, the researchers sent SMS messages to  270,000 people randomly drawn throughout Norway, while GP offices, the Norwegian National Advisory Unit on Tick-borne Disease and the Norwegian Lyme Borreliosis Disease Association also helped with the recruitment.

A total of 470 participants were examined and compared with control groups. All were over 18 years old, and had had symptoms for more than six months.

More than one in three have Lyme disease antibodies

Persistent symptoms were most prevalent in areas with a lot of ticks. In South-Western Norway, around 0.15 per cent had problems attributed to tick bites, while the percentage in Northern Norway was just 0.03 per cent.

Among the participants, 37.5 per cent had antibodies against the bacterium that most often causes Lyme disease. This shows that many people have been in contact with the bacterium and developed an immune response.

The participants also had antibodies against Borrelia and other tick-borne microbes more often than the control group. However, the study found no proven association between these antibodies and the persistent symptoms.

The study shows that 23 per cent of the participants had been diagnosed abroad. Dahlberg says this raises questions regarding the diagnostic methods used in some countries, as some laboratories use test methods that are not in line with established professional practice.

Important to get correct diagnosis

"We have thoroughly investigated whether ticks can explain the suffering in this group of participants. Since the study found no link between persistent symptoms and ongoing infection, it can contribute to more targeted follow-up and treatment. Objective findings are important for making diagnoses, and long-term antibiotic treatment beyond established practice is not recommended. An incorrect diagnosis can lead to other medical conditions being overlooked. That makes it crucial to have a thorough investigation based on objective findings," says Dahlberg.

Lyme disease can make you very ill. Dahlberg says this means people should see their doctor if they develop symptoms after a tick bite so that correct treatment can be assessed and possibly started.

Dahlberg emphasizes that the study's findings apply at the group level.

"Of course, some individuals may experience long-term ailments after tick-borne infections, such as persistent nerve damage, immune responses, or a combination of biopsychosocial factors, such as psychological stress or social circumstances. However, the study shows no indications at the group level that a large number of Norwegians experience long-term symptoms that can be attributed to persistent tick infections," Dahlberg said.

Reference: Dahlberg, A.O., Aase, A., Reiso, H. et al. Prevalence and clinical characteristics of Norwegians who report persistent health complaints attributed to tick bites or tick-borne diseases. BMC Infect Dis 25, 1663 (2025). https://doi.org/10.1186/s12879-025-12182-w

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Journal

BMC Infectious Diseases

DOI

10.1186/s12879-025-12182-w 

Method of Research

Observational study

Subject of Research

People

Article Title

Prevalence and clinical characteristics of Norwegians who report persistent health complaints attributed to tick bites or tick-borne diseases.

 

Researchers develop a high-efficiency photocatalyst using iron instead of rare metals

Nagoya University researchers used iron and blue LEDs to synthesize natural molecules, cutting the need for expensive chiral components by two-thirds.

Nagoya University

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The newly designed iron photocatalyst (front) and the previous catalyst (back)

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Credit: Yuzuru Endo

Photocatalysts facilitate chemical reactions by absorbing light. Metal-based photocatalysts are widely used in organic synthesis due to their durability and the ability to tune their function by modifying the ligands attached to the central metal atom.

Most metals used in photocatalysts, such as ruthenium and iridium, are rare and expensive. Researchers at Nagoya University, Japan, previously developed an iron-based alternative, but it required large amounts of costly chiral ligands, which act as spatial templates to determine the three-dimensional structure of chemical products.

In a recent study published in the Journal of the American Chemical Society, the researchers developed an iron catalyst that reduces the use of chiral ligands by two-thirds and enables photocatalytic reactions under energy-efficient blue LED light.

Using this new catalyst, they completed the asymmetric total synthesis of (+)-heitziamide A, a natural compound from medicinal plants that suppresses respiratory bursts.

Professor Kazuaki Ishihara, Assistant Professor Shuhei Ohmura, and graduate student Hayato Akao at Nagoya University's Graduate School of Engineering developed this technology.

 

Redefining the design of iron catalysts

In their 2023 study, the researchers developed an iron photocatalyst that used three chiral ligands per iron atom, but only one-third of these ligands contributed to enantioselectivity, making the process inefficient.

Meanwhile, the newly developed iron photocatalyst combines cost-effective achiral bidentate ligands with chiral ligands to target a specific iron(III) salt structure. The chiral ligand controls the three-dimensional configuration, while the achiral bidentate ligand tunes the catalytic activity.

Using this catalyst, researchers achieved a precise radical cation (4 + 2) cyclization, joining two molecules to form a hexagonal ring. This method enables the synthesis of 1,2,3,5-substituted adducts, structures common in natural products such as heitziamide A.

"The new catalyst design represents the definitive form of chiral iron(III) photoredox catalysts," stated Ohmura, one of the study's corresponding authors. "We believe this achievement marks a significant milestone in advancing iron-based photocatalysis."

 

Advancing artificial synthesis of (+)-heitziamide A

While artificial synthesis of heitziamide A has been previously reported, the total asymmetric synthesis of its natural enantiomer has not yet been achieved.

Using selective six-membered-ring formation with an iron photocatalyst activated by blue light, the researchers achieved the first total asymmetric synthesis of (+)-heitziamide A. This indicates that using the mirror-image catalyst would also allow the synthesis of (-)-heitziamide A, thereby enabling the selective production of both enantiomers.

 

Significance and future perspectives

The newly developed iron photocatalyst enables the precise synthesis of complex molecules, including pharmaceutical precursors, using abundant iron and blue LEDs instead of rare metals.

"Achieving the first-ever asymmetric total synthesis of (+)-heitziamide A using this catalytic reaction is a remarkable accomplishment," stated Ishihara, the study's other corresponding author. "Several additional bioactive substances can be accessed through total synthesis, with enantioselective radical cation (4 + 2) cycloaddition serving as a key step. We intend to publish follow-up papers on the asymmetric total synthesis of these compounds in the near future."

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Journal

Journal of the American Chemical Society

DOI

10.1021/jacs.5c20243 

Method of Research

Experimental study

Subject of Research

Not applicable

Article Title

A Rational Design of Chiral Iron(III) Complexes for Photocatalytic Asymmetric Radical Cation (4 + 2) Cycloadditions and the Total Synthesis of (+)-Heitziamide A

 

Researchers warn: opioids aren’t effective for many acute pain conditions

University of Sydney

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The world’s largest review of opioid pain relievers prescribed for acute pain found these medicines provide only small, short-term relief for some acute conditions and are ineffective for some others.  

Led by researchers from the University of Sydney, the study set out to review the efficacy and harms of opioid pain relievers (eg codeine, morphine, oxycodone, tramadol) compared with placebo for acute pain. The review includes 59 systematic reviews covering more than 50 acute pain conditions in children and adults, and comprehensively maps where opioids are effective and where evidence is lacking. The review provides the strongest and most comprehensive evidence to date on when opioids do and do not work for acute pain. 

The findings were published today in Drugs, one of the most prestigious journals on medicines. 

“Opioids are among the most commonly prescribed treatments for acute pain, however, our review found that they did not provide large or lasting pain relief compared with placebo for the vast majority of acute pain conditions, with pain relief typically lasting only a few hours,” said lead author Associate Professor Christina Abdel Shaheed, from the School of Public Health at the University of Sydney. 

“Overall, oral opioids were only slightly better than placebo for acute musculoskeletal pain, which they are often prescribed for, in the six to 48 hours after starting treatment. Opioids also increased the risk of side effects when used for acute musculoskeletal pain, some types of post-surgical pain or traumatic limb pain. 

“By showing that the benefits are generally small, short-lived, absent for many common conditions, and sometimes harmful, our research challenges the widely held belief that opioids are the most effective ‘go-to’ option for acute pain”.  

Key findings of the systematic overview and meta-analysis: 

• Opioids provide only small, time-limited pain relief for some pain conditions like stomach pain, dental surgery, ear procedures, traumatic limb pain, pain following childbirth, caesarean pain and bunionectomy (bunion removal). 

• Opioids were no better than placebo for some limb surgeries, kidney stone pain, pain after removal of tonsils and pain in newborns on assisted breathing devices. 

• Opioids were not consistently beneficial over time for heart-related pain, pain following hysterectomy (removal of a woman’s uterus) and topical use (patches) for dermatological (skin) pain.  

• Opioids increased the risk of side effects compared with placebo when used for acute musculoskeletal pain, traumatic limb pain and pain after some types of surgery. Side effects included nausea and vomiting. 

• Very short-term use of opioids can reduce pain for some acute conditions, however, regular use comes with a risk of harm including dependence and tolerance. Serious opioid-related harms can include misuse, overdose, hospitalisation and deaths. 

• Inadequate reporting of side effects means the true risks of these medicines are likely underestimated, urging better reporting of harms in clinical trials, and highlighting the need for safer, and more effective alternatives. 

• Overall, the evidence does not support regular opioid use for acute pain and some studies evaluated single doses, which does not reflect real world use. 

Concerns over opioid use and misuse 

“Persistent use of opioid medicines can develop quickly following first time use (sometimes within days), and may arise from regular use for acute pain,” said co-first author Dr Stephanie Mathieson from the University of Sydney’s Institute for Musculoskeletal Health and School of Pharmacy.  

“It is important that patients are informed about the potential harms from opioids when prescribed them, and that doctors prescribe these medicines judiciously (lowest effective dose for the smallest amount of time) for acute pain,” she said. 

Co-first author Associate Professor Joshua Zadro from the University's Institute for Musculoskeletal Health and School of Health Sciences added: “These findings are important for patients across all age groups who experience acute pain, doctors treating these conditions and policy makers who regulate the safe use of these medicines in the community.” 

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Journal

Drugs

DOI

10.1007/s40265-026-02284-3 

Method of Research

Systematic review

Subject of Research

People

Article Publication Date

26-Feb-2026